General, Organic, & Biological Chemistry 7TH EDITION PDF

Summary

This document is a chapter from a textbook on general chemistry. It discusses basic concepts about matter, including the characteristics, composition, and transformations of matter. The chapter also introduces various properties of matter.

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Chapter 1 Basic Concepts About Matter Section 1.1 Chemistry: The Study of Matter Chemistry Field of study concerned with the characteristics, composition, and transformations of matter Return to TOC...

Chapter 1 Basic Concepts About Matter Section 1.1 Chemistry: The Study of Matter Chemistry Field of study concerned with the characteristics, composition, and transformations of matter Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 2 Section 1.1 Chemistry: The Study of Matter Matter Anything that has mass and occupies space – Mass - Amount of matter present in a sample Includes naturally occurring living and nonliving things and synthetic materials – Examples: Plants, soil, rocks, air, bacteria, plastics Forms of energy such as heat, light, and electricity are not considered to be matter Universe is composed entirely of matter and energy Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 3 Section 1.1 Chemistry: The Study of Matter Chemistry involves the study of matter. Which statement best describes matter? a. Matter includes various forms of energy. b. Matter is visible to the naked eye. c. Matter is anything that has mass and occupies space. d. No correct responses. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 4 Section 1.1 Chemistry: The Study of Matter Chemistry involves the study of matter. Which statement best describes matter? a. Matter includes various forms of energy. b. Matter is visible to the naked eye. c. Matter is anything that has mass and occupies space. d. No correct responses. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 5 Section 1.2 Physical States of Matter Classification is based on whether the shape and volume of the matter sample are definite or indefinite – Solid – Liquid – Gas Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 6 Section 1.2 Physical States of Matter Solid Characterized by a definite shape and a definite volume Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 7 Section 1.2 Physical States of Matter Liquid Characterized by an indefinite shape and a definite volume Takes the shape of its container to the extent that it fills the container Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 8 Section 1.2 Physical States of Matter Gas Characterized by an indefinite shape and volume Completely fills its container, adopting both the container’s volume and its shape Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 9 Section 1.2 Physical States of Matter Figure 1.1 - A Comparison of the Volume and Shape Characteristics of Solids, Liquids, and Gases Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 10 Section 1.2 Physical States of Matter State of matter of a particular substance depends on: – Temperature – Surrounding pressure – Strength of the forces holding its structural particles together Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 11 Section 1.2 Physical States of Matter The physical states of matter are: a. solid, liquid, and gas. b. solid, liquid, and heat. c. solid, liquid, and electricity. d. liquid, electricity, and heat. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 12 Section 1.2 Physical States of Matter The physical states of matter are: a. solid, liquid, and gas. b. solid, liquid, and heat. c. solid, liquid, and electricity. d. liquid, electricity, and heat. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 13 Section 1.3 Properties of Matter Property Distinguishing characteristic of a substance that is used in its identification and description – Each substance has a unique set of properties that distinguishes it from all other substances Types – Physical – Chemical Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 14 Section 1.3 Properties of Matter Physical Property Characteristic that can be observed without changing the basic identity of a substance – Includes color, odor, physical state, melting point, boiling point, and hardness Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 15 Section 1.3 Properties of Matter Concept Check To measure the boiling point of a substance, a liquid must be changed into a gas. Why is boiling point considered a physical property when a gas’ appearance is much different from that of a liquid? Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 16 Section 1.3 Properties of Matter Concept Check To measure the boiling point of a substance, a liquid must be changed into a gas. Why is boiling point considered a physical property when a gas’ appearance is much different from that of a liquid? Although the appearance is different, the substance is still the same. Its chemical identity remains the same irrespective of the physical state. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 17 Section 1.3 Properties of Matter Chemical Property Characteristic that describes the way a substance undergoes or resists change to form a new substance – Example: Copper objects turn green in air Changes result from the reaction of a substance with one or more other substances – Decomposition - Change triggered by the presence of energy Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 18 Section 1.3 Properties of Matter Which of the following statements concerning the properties of matter is false? a. Properties of matter are of two types: physical and chemical. b. A physical property is a characteristic of matter that can be observed without changing its basic identity. c. A chemical property describes the way matter undergoes or resists change to form a new substance. d. One example of the physical property of water is that it can be broken down into hydrogen and oxygen gases. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 19 Section 1.3 Properties of Matter Which of the following statements concerning the properties of matter is false? a. Properties of matter are of two types: physical and chemical. b. A physical property is a characteristic of matter that can be observed without changing its basic identity. c. A chemical property describes the way matter undergoes or resists change to form a new substance. d. One example of the physical property of water is that it can be broken down into hydrogen and oxygen gases. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 20 Section 1.3 Properties of Matter Figure 1.3 - Chemical Property of Copper Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 21 Section 1.3 Properties of Matter Exercise Classify each of the following as a physical or chemical property. a. Iron metal rusts in an atmosphere of moist air. b. Mercury metal is a liquid at room temperature. c. Nickel metal dissolves in acid to produce a light green solution. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 22 Section 1.3 Properties of Matter Exercise Classify each of the following as a physical or chemical property. a. Iron metal rusts in an atmosphere of moist air. Chemical property b. Mercury metal is a liquid at room temperature. Physical property c. Nickel metal dissolves in acid to produce a light green solution. Chemical property Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 23 Section 1.4 Changes in Matter Physical Change Process in which a substance changes its physical appearance but not its chemical composition Does not lead to the formation of a new substance – Example: Boiling or freezing water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 24 Section 1.4 Changes in Matter Chemical Change Process in which chemical composition of a substance changes Involves conversion of material(s) into one or more new substances – Example: Rusting of iron objects left exposed to moist air Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 25 Section 1.4 Changes in Matter Use of the Term Physical Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 26 Section 1.4 Changes in Matter Use of the Term Chemical Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 27 Section 1.4 Changes in Matter Concept Check Which one of the following is an example of a chemical change? a. Pulverizing (crushing) rock salt b. Burning of wood c. Dissolving of sugar in water d. Melting a popsicle on a warm summer day Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 28 Section 1.4 Changes in Matter Concept Check Which one of the following is an example of a chemical change? a. Pulverizing (crushing) rock salt b. Burning of wood c. Dissolving of sugar in water d. Melting a popsicle on a warm summer day Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 29 Section 1.5 Pure Substances and Mixtures Pure Substances Versus Mixtures Pure substance: Single kind of matter that cannot be separated into other kinds of matter by any physical means – Example: Water or sucrose Mixture: Physical combination of two or more pure substances – Each substance retains its own chemical identity – Example: Salt water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 30 Section 1.5 Pure Substances and Mixtures Mixtures Have variable composition Heterogeneous mixture: Contains visibly different phases, each of which has different properties Homogeneous mixture: Contains only one visibly distinct phase, which has uniform properties throughout Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 31 Section 1.5 Pure Substances and Mixtures Figure 1.6 - Pure Substances and Mixtures Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 32 Section 1.5 Pure Substances and Mixtures Concept Check Which of the following is a homogeneous mixture? a. Pure water b. Gasoline c. Jar of jelly beans d. Soil e. Copper metal Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 33 Section 1.5 Pure Substances and Mixtures Concept Check Which of the following is a homogeneous mixture? a. Pure water b. Gasoline c. Jar of jelly beans d. Soil e. Copper metal Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 34 Section 1.5 Pure Substances and Mixtures Which of the following contain only pure substances? a. Oxygen, tap water, glass of tea b. Oxygen, glucose (a simple sugar), silver c. Glucose, chocolate chip cookies, wood d. Gasoline, dirt, rocks Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 35 Section 1.5 Pure Substances and Mixtures Which of the following contain only pure substances? a. Oxygen, tap water, glass of tea b. Oxygen, glucose (a simple sugar), silver c. Glucose, chocolate chip cookies, wood d. Gasoline, dirt, rocks Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 36 Section 1.6 Elements and Compounds Element Pure substance that cannot be broken down into simpler pure substances by chemical means such as a chemical reaction, an electric current, heat, or a beam of light – Example: Gold, silver, copper Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 37 Section 1.6 Elements and Compounds Compound Pure substance that can be broken down into two or more simpler pure substances by chemical means – Example: Water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 38 Section 1.6 Elements and Compounds Figure 1.7 - A Pure Substance can be an Element or a Compound Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 39 Section 1.6 Elements and Compounds Distinguishing Between Compounds and Mixtures Compounds Mixtures Have properties distinctly Components retain their different from those of the individual properties substances that combined to form the compound Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 40 Section 1.6 Elements and Compounds Distinguishing Between Compounds and Mixtures Compounds Mixtures Have a definite chemical Have a variable chemical composition composition Components cannot be Physical methods are separated by physical sufficient to separate the methods components – Chemical methods are required Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 41 Section 1.6 Elements and Compounds Figure 1.8 - Classifying a Sample of Matter Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 42 Section 1.6 Elements and Compounds Questions Asked to Classify a Sample of Matter Does the sample of matter have the same properties throughout? Are two or more different substances present? Can the pure substance be broken down into simpler substances? Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 43 Section 1.6 Elements and Compounds The difference between an element and a compound is: a. an element is a pure substance, whereas a compound is not. b. an element can be broken into simpler constituents by physical means, whereas a compound can not. c. an element can be broken down into a simpler substance by chemical means, whereas a compound can not. d. an element cannot be broken down into simpler substances by chemical means, whereas a compound can. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 44 Section 1.6 Elements and Compounds The difference between an element and a compound is: a. an element is a pure substance, whereas a compound is not. b. an element can be broken into simpler constituents by physical means, whereas a compound can not. c. an element can be broken down into a simpler substance by chemical means, whereas a compound can not. d. an element cannot be broken down into simpler substances by chemical means, whereas a compound can. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 45 Section 1.7 Discovery and Abundance of the Elements 118 known elements – 88 of the elements occur naturally – 30 of the elements have been synthesized Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 46 Section 1.7 Discovery and Abundance of the Elements Figure 1.10 - Abundance of Elements (in Atom Percent) in the Universe Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 47 Section 1.7 Discovery and Abundance of the Elements Figure 1.10 - Abundance of Elements (in Atom Percent) in the Earth’s Crust Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 48 Section 1.7 Discovery and Abundance of the Elements Which two elements dominate the earth’s crust and which one element dominates the universe? a. Earth’s crust: oxygen and silicon; universe: hydrogen b. Earth’s crust: oxygen and silicon; universe: nitrogen c. Earth’s crust: oxygen and nitrogen; universe: hydrogen d. Earth’s crust: oxygen and silicon; universe: nitrogen Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 49 Section 1.7 Discovery and Abundance of the Elements Which two elements dominate the earth’s crust and which one element dominates the universe? a. Earth’s crust: oxygen and silicon; universe: hydrogen b. Earth’s crust: oxygen and silicon; universe: nitrogen c. Earth’s crust: oxygen and nitrogen; universe: hydrogen d. Earth’s crust: oxygen and silicon; universe: nitrogen Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 50 Section 1.8 Names and Chemical Symbols of the Elements Chemical Symbol One- or two-letter designation for an element derived from the element’s name – Two letter symbols can be the first two letters of the element’s name – First letter of a chemical symbol is always capitalized and the second is not H – Hydrogen Ba – Barium Co – Cobalt Pb – Lead Ag – Silver Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 51 Section 1.8 Names and Chemical Symbols of the Elements Chemical Symbol Some elements have symbols that were derived from non-English names – Ag – Silver – Au – Gold – Fe – Iron – Pb – Lead – Cu – Copper Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 52 Section 1.8 Names and Chemical Symbols of the Elements Chemical symbols consist of: a. the first letter of the element’s name always in lower case. b. one- or two-letters derived from the element’s name with both letters always capitalized. c. the first two letters of the element’s name with both letters capitalized. d. one- or two-letters derived from the element’s name with the first letter capitalized and the second in lower case. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 53 Section 1.8 Names and Chemical Symbols of the Elements Chemical symbols consist of: a. the first letter of the element’s name always in lower case. b. one- or two-letters derived from the element’s name with both letters always capitalized. c. the first two letters of the element’s name with both letters capitalized. d. one- or two-letters derived from the element’s name with the first letter capitalized and the second in lower case. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 54 Section 1.9 Atoms and Molecules Atom Smallest particle of an element that can exist and still have the properties of the element Limit of chemical subdivision – 254 million atoms arranged in a straight line would extend a distance of approximately 1 inch Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 55 Section 1.9 Atoms and Molecules Molecule Group of two or more atoms that functions as a unit because the atoms are tightly bound together Behaves as a single, distinct particle Limit of physical subdivision Diatomic molecule: Contains two atoms Triatomic molecule: Contains three atoms Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 56 Section 1.9 Atoms and Molecules Homoatomic Molecule All atoms present are of the same kind Substance containing homoatomic molecules must be an element Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 57 Section 1.9 Atoms and Molecules Heteroatomic Molecule Two or more kinds of atoms are present Substances containing heteroatomic molecules must be compounds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 58 Section 1.9 Atoms and Molecules Figure 1.13 - Heteroatomic Molecules Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 59 Section 1.9 Atoms and Molecules Concept Check Classify XeF4 as: ▪ diatomic, triatomic, etc. ▪ homoatomic or heteroatomic ▪ element or compound Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 60 Section 1.9 Atoms and Molecules Concept Check Classify XeF4 as: ▪ diatomic, triatomic, etc. pentatomic ▪ homoatomic or heteroatomic heteroatomic ▪ element or compound compound Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 61 Section 1.9 Atoms and Molecules Which of the following statements is true? a. The smallest particle of an element that can exist and still have properties of the element is called an atom. b. A group of two or more atoms that function as a unit form a molecule. c. Some classifications of molecules are: diatomic, homoatomic, and heteroatomic. d. All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 62 Section 1.9 Atoms and Molecules Which of the following statements is true? a. The smallest particle of an element that can exist and still have properties of the element is called an atom. b. A group of two or more atoms that function as a unit form a molecule. c. Some classifications of molecules are: diatomic, homoatomic, and heteroatomic. d. All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 63 Section 1.10 Chemical Formulas Notation made up of the chemical symbols of: – Elements present in a compound – Numerical subscripts Indicate the number of atoms of each element present in a molecule of the compound Examples – H2O - Two atoms of hydrogen, one atom of oxygen – Ca3(PO4)2 - Three atoms of calcium, two atoms of phosphorus, eight atoms of oxygen Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 64 Section 1.10 Chemical Formulas Exercise For each of the following chemical formulas, determine how many atoms of each element are present: a. H2SO4 b. Fe2(CO3)3 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 65 Section 1.10 Chemical Formulas Exercise For each of the following chemical formulas, determine how many atoms of each element are present: a. H2SO4 two hydrogen; one sulfur; four oxygen b. Fe2(CO3)3 two iron; three carbon; nine oxygen Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 66 Section 1.10 Chemical Formulas Chemical formulas consist of: a. symbols of each element in a compound with all letters capitalized. b. symbols of each element in a compound with all letters in lower case. c. symbols of each element in a compound with numerical subscripts to indicate the number of atoms of each element in the compound. d. symbols of each element in a compound. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 67 Section 1.10 Chemical Formulas Chemical formulas consist of: a. symbols of each element in a compound with all letters capitalized. b. symbols of each element in a compound with all letters in lower case. c. symbols of each element in a compound with numerical subscripts to indicate the number of atoms of each element in the compound. d. symbols of each element in a compound. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 68 Chapter 1 Concept Question 2 You are given two cylinders, each containing a gas. You are requested to test the flammability of each gas, and you discover that one gas is very flammable, but the other gas extinguishes the flame. The two gases are _____ and _____ and are classified as a _____ and _____, respectively. a. hydrogen; methane; homoatomic molecule; heteroatomic molecule b. hydrogen; carbon dioxide; diatomic molecule; heteroatomic molecule c. neon; carbon dioxide; element; diatomic molecule d. hydrogen; oxygen; element; element Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 69 Chapter 1 Concept Question 2 You are given two cylinders, each containing a gas. You are requested to test the flammability of each gas, and you discover that one gas is very flammable, but the other gas extinguishes the flame. The two gases are _____ and _____ and are classified as a _____ and _____, respectively. a. hydrogen; methane; homoatomic molecule; heteroatomic molecule b. hydrogen; carbon dioxide; diatomic molecule; heteroatomic molecule c. neon; carbon dioxide; element; diatomic molecule d. hydrogen; oxygen; element; element Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 70 Chapter 3 Atomic Structure and the Periodic Table Section 3.1 Internal Structure of an Atom Subatomic Particle Minute particle that is a building block for atoms Types – Electron: Possesses a negative electrical charge Found outside the nucleus – Proton: Carries a positive charge equal to the electron’s negative charge – Neutron: Has no charge Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 2 Section 3.1 Internal Structure of an Atom Table 3.1 - Charge and Mass Characteristics Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 3 Section 3.1 Internal Structure of an Atom Nucleus Small, dense, positively charged center of an atom Contains all protons and neutrons Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 4 Section 3.1 Internal Structure of an Atom Charge Neutrality of an Atom Atom as a whole is electrically neutral – No net electrical charge Number of protons = Number of electrons Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 5 Section 3.1 Internal Structure of an Atom The subatomic particles of an atom are: a. protons and neutrons. b. protons and electrons. c. neutrons and electrons. d. protons, neutrons, and electrons. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 6 Section 3.1 Internal Structure of an Atom The subatomic particles of an atom are: a. protons and neutrons. b. protons and electrons. c. neutrons and electrons. d. protons, neutrons, and electrons. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 7 Section 3.2 Atomic Number and Mass Number Atomic number (Z): Number of protons in the nucleus of an atom Mass number (A): Sum of the number of protons and neutrons in the nucleus of an atom Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 8 Section 3.2 Atomic Number and Mass Number Complete Chemical Symbol Notation Mass number A Symbol Chemical symbol Atomic number Z Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 9 Section 3.2 Atomic Number and Mass Number Element Pure substance in which all atoms present have the same atomic number – Possess the same chemical properties Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 10 Section 3.2 Atomic Number and Mass Number The atomic number of an atom is: a. the sum of the number of protons in the nucleus of an atom. b. the number of neutrons in the nucleus of an atom. c. obtained from the mass number. d. the number of protons and the number of electrons in an atom. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 11 Section 3.2 Atomic Number and Mass Number The atomic number of an atom is: a. the sum of the number of protons in the nucleus of an atom. b. the number of neutrons in the nucleus of an atom. c. obtained from the mass number. d. the number of protons and the number of electrons in an atom. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 12 Section 3.3 Isotopes and Atomic Masses Isotopes Atoms of an element that have the same number of protons and electrons but different numbers of neutrons Show identical chemical properties Physical properties slightly differ as they have different masses Most elements found in nature exist in isotopic forms Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 13 Section 3.3 Isotopes and Atomic Masses Isotopes of Silicon Number of Protons = 14 Number of Protons = 14 Mass number = 28 Mass number = 29 Number of Neutrons = 14 Number of Neutrons = 15 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 14 Section 3.3 Isotopes and Atomic Masses Exercise A certain isotope X contains 23 protons and 28 neutrons. What is the mass number of this isotope? Identify the element. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 15 Section 3.3 Isotopes and Atomic Masses Exercise A certain isotope X contains 23 protons and 28 neutrons. What is the mass number of this isotope? 51 Identify the element. Vanadium Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 16 Section 3.3 Isotopes and Atomic Masses Atoms of an element that contain a different number of neutrons are known as: a. nucleophiles. b. isotopes. c. isophiles. d. neutrophiles. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 17 Section 3.3 Isotopes and Atomic Masses Atoms of an element that contain a different number of neutrons are known as: a. nucleophiles. b. isotopes. c. isophiles. d. neutrophiles. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 18 Section 3.4 The Periodic Law and the Periodic Table Periodic law – When elements are arranged in order of increasing atomic number, elements with similar chemical properties occur at periodic intervals Periodic table: Tabular arrangement of the elements in order of increasing atomic number – Elements having similar chemical properties are positioned in vertical columns Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 19 Section 3.4 The Periodic Law and the Periodic Table The Periodic Table Periods: Horizontal rows of elements Groups: Vertical columns of elements that have similar chemical properties – Groups with non-numerical names Alkali metal (IA) Alkaline earth metal (IIA) Halogen (VIIA) Noble gas (VIIIA) Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 20 Section 3.4 The Periodic Law and the Periodic Table Figure 3.3 - The Periodic Table Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 21 Section 3.4 The Periodic Law and the Periodic Table Elements are arranged in the periodic table according to: a. increasing number of neutrons. b. increasing number of neutrons and protons. c. increasing atomic number. d. increasing atomic mass unit. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 22 Section 3.4 The Periodic Law and the Periodic Table Elements are arranged in the periodic table according to: a. increasing number of neutrons. b. increasing number of neutrons and protons. c. increasing atomic number. d. increasing atomic mass unit. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 23 Section 3.5 Metals and Nonmetals Metal Element that has the characteristic properties of: – Luster – Thermal conductivity – Electrical conductivity – Malleability Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 24 Section 3.5 Metals and Nonmetals Nonmetal Element characterized by the absence of the properties of a metal Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 25 Section 3.5 Metals and Nonmetals Table 3.3 - Selected Physical Properties of Metals and Nonmetals Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 26 Section 3.5 Metals and Nonmetals Figure 3.6 - Dividing Line Between Metals and Nonmetals Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 27 Section 3.5 Metals and Nonmetals Differences between metals and nonmetals are: a. metals conduct electricity while nonmetals do not. b. metals are generally solids while nonmetals exist as gases, liquid, or solids. c. metals are malleable while nonmetals are brittle in the solid state. d. all of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 28 Section 3.5 Metals and Nonmetals Differences between metals and nonmetals are: a. metals conduct electricity while nonmetals do not. b. metals are generally solids while nonmetals exist as gases, liquid, or solids. c. metals are malleable while nonmetals are brittle in the solid state. d. all of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 29 Chapter 4 Chemical Bonding: The Ionic Bond Model Section 4.1 Chemical Bond Attractive force that holds two atoms together in a more complex unit Formed as a result of interactions between electrons found in the combining atoms Types – Ionic bonds – Covalent bonds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 2 Section 4.1 Chemical Bond Ionic Bond Formed through the transfer of one or more electrons from one atom or group of atoms to another atom or group of atoms Ionic compound: Compounds in which ionic bonds are present Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 3 Section 4.1 Chemical Bond Covalent Bond Formed through the sharing of one or more pairs of electrons between two atoms Molecular compound: Compound in which covalent bonds are present Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 4 Section 4.1 Chemical Bond Bonding Most bonds are not 100% ionic or 100% covalent – Some degree of both ionic and covalent characteristics exist Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 5 Section 4.1 Chemical Bond Fundamental Concepts of Bonding Not all electrons in an atom participate in bonding – Those that do are called valence electrons Certain arrangements of electrons are more stable than others – This is explained by the octet rule Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 6 Section 4.1 Chemical Bond An ionic bond is formed by the: a.sharing of one or more electrons between atoms. b.sharing of two or more electrons between atoms. c.transfer of one or more electrons from one atom to another. d.transfer of two or more electrons from one atom to another. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 7 Section 4.1 Chemical Bond An ionic bond is formed by the: a.sharing of one or more electrons between atoms. b.sharing of two or more electrons between atoms. c.transfer of one or more electrons from one atom to another. d.transfer of two or more electrons from one atom to another. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 8 Section 4.2 Valence Electrons and Lewis Symbols Valence Electron Electron in the outermost electron shell of a representative element or noble-gas element – Valence electrons are found in either s or p subshells in representative elements or noble gases Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 9 Section 4.2 Valence Electrons and Lewis Symbols Lewis Symbol Chemical symbol of an element surrounded by dots equal in number to the number of valence electrons present in atoms of the element Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 10 Section 4.2 Valence Electrons and Lewis Symbols Figure 4.1 - Lewis Symbols for Selected Representative and Noble-Gas Elements Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 11 Section 4.2 Valence Electrons and Lewis Symbols Concept Check Determine the number of valence electrons in each of the following elements: Ca Se C Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 12 Section 4.2 Valence Electrons and Lewis Symbols Concept Check Determine the number of valence electrons in each of the following elements: Ca 2 valence electrons (4s2) Se 6 valence electrons (4s24p4) C 4 valence electrons (2s22p2) Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 13 Section 4.2 Valence Electrons and Lewis Symbols Important Generalizations About Valence Electrons 1. Representative elements in the same group have the same number of valence electrons 2. The number of valence electrons for representative elements is the same as the Roman numeral periodic-table group number 3. The maximum number of valence electrons for any element is eight Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 14 Section 4.2 Valence Electrons and Lewis Symbols Concept Check Write Lewis symbols for the following elements: O P F Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 15 Section 4.2 Valence Electrons and Lewis Symbols Concept Check Write Lewis symbols for the following elements: O P F Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 16 Section 4.2 Valence Electrons and Lewis Symbols A valence electron is an electron in the outer-most electron shell of an atom. The shorthand method developed by scientists to represent the number of valence electrons in an atom involves the use of: a.ionic bond model. b.dot symbols. c.octet rule. d.Lewis symbols or electron-dot symbols. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 17 Section 4.2 Valence Electrons and Lewis Symbols A valence electron is an electron in the outer-most electron shell of an atom. The shorthand method developed by scientists to represent the number of valence electrons in an atom involves the use of: a.ionic bond model. b.dot symbols. c.octet rule. d.Lewis symbols or electron-dot symbols. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 18 Section 4.3 The Octet Rule Certain arrangements of valence electrons are more stable than others Valence electron configurations of the noble gases are considered the most stable of all valence electron configurations Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 19 Section 4.3 The Octet Rule Octet Rule In forming compounds, atoms of elements lose, gain, or share electrons – Produce a noble-gas electron configuration for each of the atoms involved Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 20 Section 4.3 The Octet Rule The rule that states that atoms lose, gain, or share electrons to form a noble-gas electron configuration is known as the: a.octet rule. b.electron rule. c.noble gas rule. d.bonding rule. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 21 Section 4.3 The Octet Rule The rule that states that atoms lose, gain, or share electrons to form a noble-gas electron configuration is known as the: a.octet rule. b.electron rule. c.noble gas rule. d.bonding rule. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 22 Section 4.4 The Ionic Bond Model Ion Atom (or group of atoms) that is electrically charged as a result of the loss or gain of electrons Negatively charged ion - Atom gains one or more electrons Positively charged ion - Atom loses one or more electrons Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 23 Section 4.4 The Ionic Bond Model Figure 4.3 - Positive and Negative Ions Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 24 Section 4.4 The Ionic Bond Model Concept Check Give the chemical symbol for each of the following ions. a. The ion formed when a potassium atom loses one electron. b. The ion formed when a sulfur atom gains two electrons. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 25 Section 4.4 The Ionic Bond Model Concept Check Give the chemical symbol for each of the following ions. a. The ion formed when a potassium atom loses one electron. K+ b. The ion formed when a sulfur atom gains two electrons. S2– Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 26 Section 4.4 The Ionic Bond Model Atoms can either lose or gain electrons resulting in the formation of: a.ions. b.cations. c.anions. d.all of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 27 Section 4.4 The Ionic Bond Model Atoms can either lose or gain electrons resulting in the formation of: a.ions. b.cations. c.anions. d.all of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 28 Section 4.5 The Sign and Magnitude of Ionic Charge Atoms tend to gain or lose electrons until they have obtained an electron configuration that is the same as that of a noble gas – Example: Na+ (1s22s22p63s1) Loss of one electron gives it the electron configuration of neon – Ne (1s22s22p6) Gain of seven electrons gives it the electron configuration of argon – Ar (1s22s22p63s23p6) Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 29 Section 4.5 The Sign and Magnitude of Ionic Charge Guidelines of Electron Loss and Gain by Atoms of Elements 1. Metal atoms containing one, two, or three valence electrons tend to lose electrons to acquire a noble-gas electron configuration Group Charge IA 1+ IIA 2+ IIIA 3+ Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 30 Section 4.5 The Sign and Magnitude of Ionic Charge Guidelines of Electron Loss and Gain by Atoms of Elements 2. Nonmetal atoms containing five, six, or seven valence electrons tend to gain electrons to acquire a noble-gas electron configuration Group Charge VIIA 1- VIA 2- VA 3- Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 31 Section 4.5 The Sign and Magnitude of Ionic Charge Guidelines of Electron Loss and Gain by Atoms of Elements 3. Elements in Group IVA occupy unique positions relative to the noble gases – Could gain or lose four electrons to attain a noble-gas structure Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 32 Section 4.5 The Sign and Magnitude of Ionic Charge Isoelectronic Species An atom and an ion, or two ions, that have the same number and configuration of electrons – Example: The electronic configuration of N3-, O2-, F-, Na+, Mg2+, and Al3+ is 1s22s22p6 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 33 Section 4.5 The Sign and Magnitude of Ionic Charge Table 4.1 - Isoelectronic Species Ne and Mg2+ Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 34 Section 4.5 The Sign and Magnitude of Ionic Charge Concept Check Choose an alkali metal, an alkaline earth metal, a noble gas, and a halogen so that they constitute an isoelectronic series when the metals and halogen are written as their most stable ions. What is the electron configuration for each species? Determine the number of electrons for each species. Determine the number of protons for each species. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 35 Section 4.5 The Sign and Magnitude of Ionic Charge What is the electron configuration of the magnesium ion? a.1s22s22p6 b.1s22s22p63s2 c.1s22s22p63s1 d.1s22s2p6 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 36 Section 4.5 The Sign and Magnitude of Ionic Charge What is the electron configuration of the magnesium ion? a.1s22s22p6 b.1s22s22p63s2 c.1s22s22p63s1 d.1s22s2p6 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 37 Section 4.6 Lewis Structures for Ionic Compounds Formation of an Ionic Compound Ion formation requires the presence of: – A metal that can donate electrons – A nonmetal that can accept electrons Electrons lost by the metal are the same ones gained by the nonmetal Positive and negative ions simultaneously formed from an electron transfer attract one another Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 38 Section 4.6 Lewis Structures for Ionic Compounds Lewis Structure Combination of Lewis symbols that represents either the transfer or the sharing of electrons in chemical bonds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 39 Section 4.6 Lewis Structures for Ionic Compounds Reaction Between Sodium and Chlorine Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 40 Section 4.6 Lewis Structures for Ionic Compounds Reaction Between Sodium and Oxygen Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 41 Section 4.6 Lewis Structures for Ionic Compounds Reaction Between Calcium and Chlorine Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 42 Section 4.6 Lewis Structures for Ionic Compounds What is the correct definition of a Lewis structure? a.Lewis structure is a combination of Lewis symbols representing the transfer of electrons in chemical bonds. b.Lewis structure is a combination of Lewis symbols representing the sharing of electrons in chemical bonds. c.Lewis structure is a combination of Lewis symbols that represents either the transfer or sharing of electrons in chemical bonds. d.Lewis structure is a combination of Lewis symbols representing an ionic bond. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 43 Section 4.6 Lewis Structures for Ionic Compounds What is the correct definition of a Lewis structure? a.Lewis structure is a combination of Lewis symbols representing the transfer of electrons in chemical bonds. b.Lewis structure is a combination of Lewis symbols representing the sharing of electrons in chemical bonds. c.Lewis structure is a combination of Lewis symbols that represents either the transfer or sharing of electrons in chemical bonds. d.Lewis structure is a combination of Lewis symbols representing an ionic bond. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 44 Section 4.7 Chemical Formulas for Ionic Compounds Ionic compounds are always neutral – No net charge is present Ratio in which positive and negative ions combine is the ratio that achieves charge neutrality for the resulting compound Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 45 Section 4.7 Chemical Formulas for Ionic Compounds Writing Chemical Formulas for Ionic Compounds 1. Symbol for the positive ions is always written first 2. Charges on the ions that are present are not shown in the formula 3. Subscripts in the formula give the combining ratio for the ions Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 46 Section 4.7 Chemical Formulas for Ionic Compounds Example Compound formed between Na+ and P3– – Na+ and P3– ions combine in a 3-to-1 ratio – Formula - Na3P Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 47 Section 4.7 Chemical Formulas for Ionic Compounds Concept Check Determine the chemical formula for the compound that is formed when each of the following pairs of ions interact. Ba2+ and Cl– Fe3+ and O2– Pb4+ and O2– Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 48 Section 4.7 Chemical Formulas for Ionic Compounds Concept Check Determine the chemical formula for the compound that is formed when each of the following pairs of ions interact. Ba2+ and Cl– BaCl2 Fe3+ and O2– Fe2O3 Pb4+ and O2– PbO2 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 49 Section 4.7 Chemical Formulas for Ionic Compounds What is the correct formula for the combination of Al3+ and Cl-? a.Al3Cl b.Al2Cl3 c.AlCl3 d.Al3Cl1 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 50 Section 4.7 Chemical Formulas for Ionic Compounds What is the correct formula for the combination of Al3+ and Cl-? a.Al3Cl b.Al2Cl3 c.AlCl3 d.Al3Cl1 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 51 Section 4.8 The Structure of Ionic Compounds Solid Ionic Compounds Consist of positive and negative ions arranged in such a way that each ion is surrounded by nearest neighbors of the opposite charge Any given ion is bonded by electrostatic attractions to all the other ions of opposite charge immediately surrounding it Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 52 Section 4.8 The Structure of Ionic Compounds Figure 4.4 - Two-Dimensional Cross-Section and Three-Dimensional View of Sodium Chloride (NaCl) Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 53 Section 4.8 The Structure of Ionic Compounds Formula Unit Smallest whole-number repeating ratio of ions present in an ionic compound that results in charge neutrality Chemical formulas for ionic compounds represent the simplest ratio of ions present Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 54 Section 4.8 The Structure of Ionic Compounds Figure 4.5 - Cross-Section of the Structure of the Ionic Solid NaCl Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 55 Section 4.8 The Structure of Ionic Compounds What term is used to refer to the smallest whole-number repeating ratio of ions present in an ionic compound? a.Molecule unit b.Ion unit c.Ion molecule unit d.Formula unit Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 56 Section 4.8 The Structure of Ionic Compounds What term is used to refer to the smallest whole-number repeating ratio of ions present in an ionic compound? a.Molecule unit b.Ion unit c.Ion molecule unit d.Formula unit Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 57 Section 4.9 Recognizing and Naming Binary Ionic Compounds Binary compounds: Compounds composed of two elements Binary ionic compounds: Compound in which one element present is a metal and the other is a nonmetal – Metal is present as the positive ion and the nonmetal is present as the negative ion Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 58 Section 4.9 Recognizing and Naming Binary Ionic Compounds Naming Binary Ionic Compounds Full name of the metallic element is given first – This is followed by a separate word containing the stem of the nonmetallic element name and the suffix –ide Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 59 Section 4.9 Recognizing and Naming Binary Ionic Compounds Table 4.2 - Names of Selected Common Nonmetallic Ions Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 60 Section 4.9 Recognizing and Naming Binary Ionic Compounds Examples KCl Potassium chloride MgBr2 Magnesium bromide CaO Calcium oxide Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 61 Section 4.9 Recognizing and Naming Binary Ionic Compounds Naming Ionic Compounds for Metals with Variable Charges Transition and inner transition metals form more than one type of positive charge Charge on the metal ion must be incorporated into the name – Accomplished by using roman numerals – Charge on the nonmetal ion present can be used to calculate the charge on the metal ion if the latter is unknown Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 62 Section 4.9 Recognizing and Naming Binary Ionic Compounds Examples CuBr Copper(I) bromide FeS Iron(II) sulfide PbO2 Lead(IV) oxide Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 63 Section 4.9 Recognizing and Naming Binary Ionic Compounds Figure 4.8 - Metallic Elements That Exhibit a Fixed Ionic Charge Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 64 Section 4.9 Recognizing and Naming Binary Ionic Compounds Exercise Name each of the following compounds: K2S Fe2O3 CoCl2 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 65 Section 4.9 Recognizing and Naming Binary Ionic Compounds Exercise Name each of the following compounds: K2S potassium sulfide Fe2O3 iron(III) oxide CoCl2 cobalt(II) chloride Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 66 Section 4.9 Recognizing and Naming Binary Ionic Compounds What is a binary ionic compound? a.An ionic compound composed of a metal and a nonmetal. b.An ionic compound composed of two metals. c.An ionic compound composed of two nonmetals. d.An ionic compound composed of two metals and two nonmetals. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 67 Section 4.9 Recognizing and Naming Binary Ionic Compounds What is a binary ionic compound? a.An ionic compound composed of a metal and a nonmetal. b.An ionic compound composed of two metals. c.An ionic compound composed of two nonmetals. d.An ionic compound composed of two metals and two nonmetals. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 68 Section 4.10 Polyatomic Ions Ions formed from a group of atoms through loss or gain of electrons Stable and maintain their identities during chemical reactions Examples of compounds containing polyatomic ions – NaOH Sodium hydroxide – Mg(NO3)2 Magnesium nitrate – (NH4)2SO4 Ammonium sulfate Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 69 Section 4.10 Polyatomic Ions Generalizations 1. Most polyatomic ions have a negative charge – Exceptions: H3O+ (hydronium) and NH4+ (ammonium) 2. Most of the ions contain oxygen atoms – Exceptions: CN− (cyanide) and NH4+ (ammonium) 3. Two of the negatively charged polyatomic ions, OH– and CN–, have names ending in –ide and the rest of them have names ending in –ate Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 70 Section 4.10 Polyatomic Ions Generalizations 3. Two positive ions have names that end in –ium – Hydronium (H3O+) and ammonium (NH4+) 4. A number of pairs of ions exist wherein one member of the pair differs from the other by having a hydrogen atom present – In such pairs, the charge on the ion that contains hydrogen is always 1 less than that on the other ion Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 71 Section 4.10 Polyatomic Ions What is a polyatomic ion? a.An ion formed by a group of positive and negative ions. b.An ion formed from a group of atoms held together by covalent bonds and is positively or negatively charged. c.An ion formed by a group of positive and negative ions held together by covalent bonds. d.All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 72 Section 4.10 Polyatomic Ions What is a polyatomic ion? a.An ion formed by a group of positive and negative ions. b.An ion formed from a group of atoms held together by covalent bonds and is positively or negatively charged. c.An ion formed by a group of positive and negative ions held together by covalent bonds. d.All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 73 Section 4.11 Chemical Formulas and Names for Ionic Compounds Containing Polyatomic Ions Determined in the same way as those for ionic compounds that contain monatomic ions Positive and negative charges present must add to zero – Na+ and OH– form NaOH – Mg2+ and NO3– form Mg(NO3)2 – NH4+ and SO42– form (NH4)2SO4 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 74 Section 4.11 Chemical Formulas and Names for Ionic Compounds Containing Polyatomic Ions Exercise Which of the following compounds is named incorrectly? a. KNO3 potassium nitrate b. TiO2 titanium(II) oxide c. Sn(OH)4 tin(IV) hydroxide d. (NH4)2SO3 ammonium sulfite e. CaCrO4 calcium chromate Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 75 Section 4.11 Chemical Formulas and Names for Ionic Compounds Containing Polyatomic Ions Exercise Which of the following compounds is named incorrectly? a. KNO3 potassium nitrate b. TiO2 titanium(II) oxide c. Sn(OH)4 tin(IV) hydroxide d. (NH4)2SO3 ammonium sulfite e. CaCrO4 calcium chromate titanium(IV) oxide Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 76 Section 4.11 Chemical Formulas and Names for Ionic Compounds Containing Polyatomic Ions What is the correct chemical formula for the combination of ammonium(NH4+) and carbonate (CO32-) ions? a.2(NH4)CO3 b.2NH4CO3 c.(NH4)2CO3 d.NH4CO3 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 77 Section 4.11 Chemical Formulas and Names for Ionic Compounds Containing Polyatomic Ions What is the correct chemical formula for the combination of ammonium(NH4+) and carbonate (CO32-) ions? a.2(NH4)CO3 b.2NH4CO3 c.(NH4)2CO3 d.NH4CO3 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 78 Chapter 4 Concept Question 1 After placing a soft, lustrous, and malleable material in a container of yellowish gas, a violent reaction occurs leaving a white crystalline material. You decide to break the rule “Never taste chemicals in a laboratory” and find that it tastes very salty. Which of the following is correct? a.Not enough information is provided to determine what the two materials and product are. b.The two materials are likely to be the elements sodium and chlorine reacting to share electrons to produce the molecular compound sodium chloride. c.The two materials are likely to be the elements sodium and chlorine, both reacting by a transfer of electrons to produce the ionic compound sodium chloride. d.The two materials are homogenous compounds reacting to produce an unidentifiable salt. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 79 Chapter 4 Concept Question 1 After placing a soft, lustrous, and malleable material in a container of yellowish gas, a violent reaction occurs leaving a white crystalline material. You decide to break the rule “Never taste chemicals in a laboratory” and find that it tastes very salty. Which of the following is correct? a.Not enough information is provided to determine what the two materials and product are. b.The two materials are likely to be the elements sodium and chlorine reacting to share electrons to produce the molecular compound sodium chloride. c.The two materials are likely to be the elements sodium and chlorine, both reacting by a transfer of electrons to produce the ionic compound sodium chloride. d.The two materials are homogenous compounds reacting to produce an unidentifiable salt. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 80 Chapter 4 Concept Question 2 Fill in the following table with the correct information. a.1. Sodium carbonate; 2. Magnesium carbonate; 3. Na3PO4; 4. MgPO4 b.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. Na3PO4; 4. Mg3(PO4)2 c.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. Na(PO4)3; 4. Mg3PO4 d.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. NaPO4; 4. Mg3(PO4)2 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 81 Chapter 4 Concept Question 2 Fill in the following table with the correct information. a.1. Sodium carbonate; 2. Magnesium carbonate; 3. Na3PO4; 4. MgPO4 b.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. Na3PO4; 4. Mg3(PO4)2 c.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. Na(PO4)3; 4. Mg3PO4 d.1. Sodium hydrogen carbonate; 2. Magnesium bicarbonate; 3. NaPO4; 4. Mg3(PO4)2 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 82 → → → → → → → → ⚬ University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Module 2 Review of Organic Chemistry Virtual Consultation Time: ____________ Overview: In this module, we will cover concepts on organic chemistry and organic compounds in preparation for higher chemistry throughout the duration of this course, CHEM7. The topics of this module includes introduction to hydrocarbons and the different functional groups, hybridization, stereochemistry of organic compounds and introduction to different organic reactions. Topics to be covered: 2.1. Hydrocarbons 2.4. Stereochemistry 2.2. Hybridization 2.5. Organic reactions 2.3. Functional Groups Learning Outcomes: 1. Name the organic compound 2. Identify the hybridization of a functional group 3. Identify the functional groups 4. Identify stereogenic centers, chirality and mirror images 5. Classify the type of organic reaction Learning Plan: 1.1. Hydrocarbons : synchronous and asynchronous, Google Meet (20mins), seatwork 1.2. Hybridization: synchronous and asynchronous, Google Meet (5mins), seatwork 1.3. Functional groups: synchronous and asynchronous, Google Meet (5mins) forum discussion via Google classroom, seatwork, 1.4. Stereochemistry: synchronous and asynchronous Google Meet (15mins), seatwork 1.5. Organic reactions: synchronous and asynchronous, Google Meet (5mins), seatwork What is Organic Chemistry? Organic chemistry is the chemistry of compounds that contain the element carbon 2.1 Hydrocarbons CHEM 7 Module 2: Review of Organic Chemistry 1/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS What is so special about Carbon? Carbon can form single, double and triple covalent bonds. Because carbon assumes a stable tetrahedral shape, it can form long chain of carbon single bonds without falling apart. A B C D Figure 1. Four ways Carbon can bond to other atoms. (A) Four single bonds to other atoms. (B) Two single bonds and one double bond. (C) Two double bonds. (D) One single bond and one triple bond. (Stoker) Hydrocarbons are compounds made up of only the elements carbon (C) and hydrogen (H). They may be aliphatic or aromatic.3 Four classes of hydrocarbons: 1. Alkanes (aliphatic) 3. Alkynes (aliphatic) 2. Alkenes (aliphatic) 4. Arenes (aromatic) Table 1 shows the comparison of 4 classes of hydrocarbons Aliphatic hydrocarbons are acylic hydrocarbons that may be long or short chained and may or may not contain a double bond or a triple bond. Aromatic hydrocarbons are those compounds that usually contain the phenyl group or other cyclic unsaturated hydrocarbons that satisfy the criteria of aromaticity and Hückel’s Rule. CHEM 7 Module 2: Review of Organic Chemistry 2/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Hydrocarbons may be classified whether they are saturated or unsaturated. When all the carbon-carbon bonds are single bonds, they are termed as saturated carbons. It means the compound is saturated with hydrogen. When the compound contains double bonds, triple bonds, or both, the compound is an unsaturated hydrocarbon. This means that this molecules has lesser hydrogens. Molecular Representations A B C D Figure 3. Different ways of writing structural formula of organic compounds (Klein): (A) Kekule structure, (B) Partially condensed, (C) Condensed structure and (D) Molecular Formula. Kekule structures (also known as expanded structural formula) are Lewis structures that uses lines to represent the covalent bonds but still shows all atoms and lone pair electrons. In partially condensed structures, only the bonds with hydrogens are no longer presented. Unlike Kekule and partially condensed, the condensed structure no longer presents any covalent bonds but the atoms are positioned in the same way as the original carbon-carbon backbone. Table 2 shows the comparison of Kekule and skeletal structure.1 However, writing large and complex molecules will be taxing if done using Kekule structures. The bond-line structures or skeletal structures is a structural formula that shows the arrangement and bonding of carbon atoms present in an organic molecule but does not show the hydrogen atoms attached to the carbon atoms 1. They not only simplify the drawing process but also are easier to read.4 CHEM 7 Module 2: Review of Organic Chemistry 3/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Bond-line structures (also know as skeletal structures or line-angle structures) are drawn in a zigzag format ( ), where each corner or endpoint represents a carbon atom. Double bonds are shown with two lines, and triple bonds are shown with three lines.4 Ex. Each of the following compounds has 6 carbon atoms4 Ex. Both compounds are composed of 4 carbons but one has a double bond on C2-C3 while the other has a triple bond Carbon normally forms 4 covalent bonds and has no unshared pairs of electrons. Nitrogen normally forms 3 covalent bonds and has 1 unshared pair of electrons. Oxygen normally forms 2 covalent bonds and has 2 unshared pairs of electrons. Hydrogen forms 1 covalent bond and has no unshared pairs of electrons. A halogen (fluorine, chlorine, bromine, and iodine) normally forms one covalent bond and has three unshared pairs of electrons. Figure 4. Lewis structures of how common organic elements bond. 5 Naming hydrocarbons Table 3 shows the assigned prefix for its designated carbon number in naming hydrocarbons.1 In naming parent chain hydrocarbons: (1) Identify the number of carbons on the parent chain (2) Assign the prefix according to the number of carbon atoms (3) Add –ane after the prefix for alkanes, –ene for alkenes and –yne for alkynes CHEM 7 Module 2: Review of Organic Chemistry 4/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS (4) For alkenes and alkynes with more than 3 carbons on the parent chain, a carbon number must be assigned depending on the position of the double bond or triple bond in the given structure. If the carbon number is 3 or less, the name will remain the same as the parent chain regardless of the position of the double bond or triple bond. Ex. Name the following hydrocarbons. Figure 5. Formula of naming of organic compound.5 When naming branched hydrocarbons: (1) Identify the parent chain (longest chain of carbon-carbon bond) and identify the functional group of the parent chain (2) Assign numbers on the parent chain in such a way that the assignment of the assignment of the substituents will have the least sum (3) Identify the number of carbon on the substituents and name it in the same manner as the parent chain, but instead of assigning –ane/-ene/-yne, substituents are named with –yl (4) Name: substituents + parent chain CHEM 7 Module 2: Review of Organic Chemistry 5/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Ex. Name the following branching hydrocarbons. Watch these supplemental videos: The Organic Chemistry Tutor https://youtu.be/O8wKk6wkcEs Khan Academy https://www.khanacademy.org/science/organic-chemistry/bond-line-structures- alkanes-cycloalkanes https://www.khanacademy.org/science/organic-chemistry/alkenes-alkynes Seatwork: 2.2 Hybridization How are single bonds, double bonds and triple bonds formed? Single bonds – is formed by the formation of a σ-bond (sigma bond). A σ-bond can be formed by the overlapping of orbitals in three ways: s-s orbitals, s-p orbitals and p-p orbitals. A Figure 6. Overlapping of orbitals in a sigma bond. (A) overlapping of two s orbitals such as H-H, (B) B overlapping of two p orbitals such as F-F, O-O, and (C) overlapping of one s and one p orbital such as in the case of H-F or C-H bond (image by chegg.com) C CHEM 7 Module 2: Review of Organic Chemistry 6/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS This phenomenon of overlapping of atomic orbitals is called hybridization. In the carbon atom’s electronic configuration in the ground state, the carbon atom only has two unpaired electron. In order for the carbon atom to satisfy the octet rule in bond formation, the electrons have to be in an excited state for it to have 4 unpaired electrons to be capable of forming 4 bonds (figure 7). Figure 7. Electron configuration of carbon atom in excited state.3 How the four bonds are formed depends on the hybridization of the atom. When carbon forms four single bonds, the hybridization of the bond is sp3 because the bond was formed from one s orbital and three p orbitals such as in the case of methane. The arrangement of electron pairs in all the bonds follows a stable tetrahedral geometry, (bond angle of 109.5°). This alone already justifies why carbon is capable of making long chains of carbon-carbon bonds. (A) (B) Figure 8. (A) Formation of four sp3 hybrid orbitals. (B) Kekule structure of ethane and sp3 bond diagram.3,4 The formation of a double bond is composed of a σ―bond and a π―bond (pi bond). A π―bond is formed when the p orbitals in the same axis of two different atoms overlap such as px―px or py―py to form the π bond. When an atom contains a π-bond, this atom is sp2 hybridized since it is composed of one s orbital and two p orbitals to hybridize. CHEM 7 Module 2: Review of Organic Chemistry 7/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Figure 9. Formation of sp2 hybrid orbitals.3 When carbon is in sp2 hybridization, the geometry of the hybridized carbon atom assumes a trigonal planar geometry since it will only have three groups with no lone pair electrons. Hence, sp2 hybridized atoms will possess a bond angle close to that of a trigonal planar (120°) (figure 9A). When only one s and one p orbital will hybridize (to form sp hybridization) leaving 2 p orbitals unhybridized and available to overlap, this will create one σ-bond and two π-bonds. When two carbons participate in this orientation, this will give rise to the triple bond (see also figure 1D). CHEM 7 Module 2: Review of Organic Chemistry 8/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines www.usa.edu.ph COLLEGE OF LIBERAL ARTS, SCIENCES, AND EDUCATION DEPARTMENT OF CHEMISTRY AND PHYSICS Figure 10. Electronic configuration and orbital overlapping of sp hybridization.3,4 Going back to Figure 1 of this module, an atom can also have an sp hybridization using double bonds only (figure 1C) as long as the hybridized carbon possess two π- bonds. Since sp2 and sp hybridization contains lesser hydrogens, these hydrocarbons are unsaturated. Practice: https://www.khanacademy.org/science/chemistry/chemical-bonds/hybridization-and- hybrid-orbitals-chemistry/e/bond-hybridization-quiz http://www.sciencegeek.net/APchemistry/Quizzes/Hybridization/ 2.3 Functional Groups Functional groups are atoms or groups of atoms of an organic molecule that undergo predictable chemical reactions. Compounds having the same functional group, in whatever organic molecule it occurs, undergoes the same types of chemical reactions. CHEM 7 Module 2: Review of Organic Chemistry 9/17 University of San Agustin General Luna St., Iloilo City 5000, Philippines

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