CHEM101 General Chemistry I Fall 2024-2025 PDF

[email protected] Textbook Chemistry, The Central Science, 15th edition, By Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, Catherine, J. Murphy, Patrick M. Woodward, Matthew W. Stoltzfus, Pearson Press, USA (9781292407586-Mastering Chemistry Brown Chemistry GE 15e) The Atomic The...

[email protected] Textbook Chemistry, The Central Science, 15th edition, By Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, Catherine, J. Murphy, Patrick M. Woodward, Matthew W. Stoltzfus, Pearson Press, USA (9781292407586-Mastering Chemistry Brown Chemistry GE 15e) The Atomic Theory In the fifth century B.C. Democritus & Greek philosophers proposed: all matter is made up of very small indivisible particles. Named them as «Atomos», meaning uncuttable or indivisible. This idea was not quite accepted by others; Plato and Aristotle! Aristotelean philosopy dominated for many centuries; -> 4 elements + the aether Still, the notion of atoms endured and reemerged in seventeenth century. Experiments in the eighteenth and nineteenth centuries led to an organized atomic theory by John Dalton in the early 1800s: – The law of constant composition – The law of conservation of mass – The law of multiple proportions  The Law of Constant Composition (Law of Definite Proportions) – Joseph Proust – 1799: -> Compounds have a definite composition. That means that the relative number of atoms of each element in the compound is the same in any sample. All samples of a compound have the same composition – the same proportion by mass of the constituent elements. -> The numbers of atoms of the elements in a given compound must always exist in the same ratio. Water H2O -> This law was one of the laws on which Dalton’s atomic theory was based. Carbon dioxide CO2  The Law of Conservation of Mass – Antoine Lavoisier – 1774 The total mass of substances present after a chemical reaction is the same as the total mass of substances before the reaction.  Matter is neither created nor destroyed in a chemical reaction. Atoms of element X Atoms of element Y Compound of element X and Y 8X + 4Y -> 4 X2Y -> This law was one of the laws on which Dalton’s atomic theory was based.  Law of Multiple Proportions Dalton’s Atomic theory is also connected with another law, called the Law of Multiple Proportions: If two elements can combine to form more than one compound, the masses of one element that can combine with a fixed mass of the other element are in ratios of small whole numbers. Carbon atom Oxygen atom If two elements, A and B, form more than one compound, the masses of B that combine with a given mass of A are in the ratio of small whole Carbon monoxide numbers. CO John Dalton discovered this law while developing his atomic theory. When two or more compounds exist from the same elements, they can not have the same relative number of atoms. Carbon dioxide CO2  Law of Multiple Proportions In forming carbon monoxide, 12.0 g of carbon combines with 16.0 g of oxygen. In forming carbon dioxide, 12.0 g of carbon combines with 32.0 g of oxygen. Thus, the ratio of the masses of oxygen per gram of carbon in the two compounds is 2:1. Dalton’s atomic theory: carbon dioxide contains twice as many atoms of oxygen per carbon atom than does carbon monoxide. Carbon atom Oxygen atom Carbon monoxide O 1 = = Ratio of mass of CO C 1 oxygen in carbon dioxide to oxygen in carbon Carbon dioxide O 2 monoxide is 2:1 = = CO2 C 1 Schoolworkhelper. (2023, May 3). Timeline for Atomic Theory Development | SchoolWorkHelper. SchoolWorkHelper. https://schoolworkhelper.net/timeline-for-atomic-theory- development/ The History of the Atom – theories and models. (2023, September 13). Compound Interest. https://www.compoundchem.com/2016/10/13/atomicmodels/ Postulates of Dalton’s Atomic Theory Evolution of Atomic Theory On Dalton’s Atomic Theory, atom can be defined as the basic unit of an element that can enter into chemical combination. However, Dalton was only partially correct about these particles that make up matter. As scientists developed new methods to examine the nature of matter, it was understood that the atom had a more complex structure inside. Although atoms cannot be broken down further by ordinary chemical or physical processes, they are indeed composed of smaller subatomic particles. Discoveries: Electrons and cathode rays Radioactivity Nucleus, protons, and neutrons The Electron (Experiments with Cathode Rays) During the mid-1800s, scientists began to study electrical discharge through a glass tube pumped almost empty of air. Streams of negatively charged particles were found to emanate from cathode tubes, causing fluorescence. J. J. Thomson is credited with their discovery (1897). He found that the cathode rays had mass and also that they were negatively charged. The Electron Thomson used his cathode-ray tube together with electrically charged plates and a magnet. The cathode ray was attacted to the positively charged plate and repelled by the negatively charged plate. So this means that cathode rays were negatively charged. Cathode rays were later classified as negatively charged particles known as electrons. Thomson measured the charge/mass ratio of the electron to be 1.76 × 108 coulombs/gram (C/g). (1906 Nobel Prize in Physics, for discovery of electrons) Millikan Oil-Drop Experiment (Electrons) -> the charge/mass ratio of the electron was known -> determination of either the charge or the mass of an electron would yield the other. Millikan’s oil-drop apparatus 1, marked as public Robert Millikan determined the charge on the electron domain, more details on Wikimedia Commons in 1909. (1923 Nobel Prize in Physics, for determining the charge of the electron) Radioactivity Radioactivity is the spontaneous emission of high-energy radiation by an atom. It was first observed by Henri Becquerel. Marie Curie and Pierre Curie also studied it. Discovery of radiation showed that the atom had more subatomic particles and energy associated with it. Radioactivity In 1896 the French scientist Henri Becquerel discovered that a compound of uranium spontaneously emits high-energy radiation. Nobel foundation, Henri Becquerel 1903, marked as public domain His student Marie Curie suggested the name radioactivity to describe this spontaneous emission of particles and/or radiation. At Becquerel’s suggestion, Marie Curie and her husband, Pierre, began experiments to identify and isolate the source of radioactivity in the compound. They concluded that it was the uranium atoms. In 1903, Henri Becquerel, Marie Curie, and her husband, Pierre, were jointly awarded the Nobel Prize in Physics for their pioneering work on radioactivity. In 1911, Marie Curie won a second Nobel Prize, in Chemistry, for her discovery of the elements polonium and radium. Vitold Muratov (https://commons.wikimedia.org/wiki/File:Marie_et_Pierre_Curie.jpg), „Marie et Pierre Curie“, https://creativecommons.org/licenses/by-sa/3.0/legalcode Radioactivity Since then, any element that spontaneously emits radiation is described as radioactive. Further studies on radioactivity, principally by the British scientist Ernest Rutherford led to the discovery of three types of radiation, produced by the decay, or breakdown of radioactive substances: Alpha (α) radiation : α particles, positively charged Beta (β) radiation : β particles, negatively charged Gamma (γ) radiation: consists of high-energy photons, has no charge The Atom, circa 1900 Atoms contain electrons To be electrically neutral, an atom must Atoms are electrically neutral contain an equal number of positive and negative charges. Thomson’s Model of The Atom – The Plum Pudding -> featured a positive sphere of matter with negative electrons embedded in it. named after a traditional English dessert. Dennis Sylvester Hurd (https://commons.wikimedia.org/wiki/File:Plum_Pudding.jpg), „Plum Pudding“, https://creativecommons.org/publicdomain/zero/1.0/legalcode Discovery of the Nucleus Ernest Rutherford, working together with Hans Geiger and Ernest Marsden, used α (alpha) particles to probe the structure of the atom. Performed experiments using very thin foils of gold as targets for α (alpha) particles from a radioactive source and observed the pattern of scatter of the particles.  Hans Geiger Geiger counter (also called the Geiger-Müller counter): for detecting and measuring ionizing radiation real name: Matylda Sęk pl.wiki: Cygaretka commons: Cygaretka (https://commons.wikimedia.org/wiki/File:Portable_Geiger_counter_series_900_mini-monitor.jpg), „Portable Geiger counter series 900 mini-monitor“, https://creativecommons.org/licenses/by-sa/3.0/legalcode The Nuclear Atom E. Rutherord: 1908 Nobel Prize in Chemistry If Thompson’s model was accurate, the particles should have experienced only very minor deflections and passed Thompson’s Model right through. But Rutherford’s alpha scattering experiments showed otherwise. -> most of the particles passed through the foil unscattered because they did not encounter the tiny nucleus of any gold atom. Rutherford’s Nuclear Model -> but, when an α particle came close to a gold nucleus, the repulsion between the highly positive charge of the gold nucleus and the positive charge of the α particle was strong enough to deflect the particle.  The Nuclear Atom Rutherford postulated the Nuclear Model of the atom : A very small, dense positive center with the electrons around the outside. Most of the mass of the atom and all of its positive charge reside in this center, he called the nucleus. Most of the volume of an atom is empty space. Atoms are very small; The Planetary Model 1–5 Å or 100–500 pm. Other subatomic particles (protons and neutrons in the nucleus) were Valkurare (https://commons.wikimedia.org/wiki/File:Átomo_de_Rutherford. discovered. png), „Átomo de Rutherford“, https://creativecommons.org/licenses/by-sa/4.0/legalcode The Nucleus – Proton & Neutron The positively charged particles in the nucleus are called protons. (Rutherford -1919) A proton has the same quantity of charge as an electron, but an opposite charge. mass of proton is 1840 × mass of electron Yet, the nucleus contains another subatomic particle: In 1932, James Chadwick discovered neutrons. Located in the nucleus, the neutrons are electrically neutral, with a mass slightly greater than protons. (1935 Noble Prize in Physics)  Properties of Subatomic Particles Coulomb Charge Unit Particle Mass ( g ) Charge Charge Electron * 9.10938 × 10 – 28 – 1.6022 × 10 – 19 –1 Proton 1.67262 × 10 – 24 + 1.6022 × 10 – 19 +1 Neutron 1.67493 × 10 – 24 0 0 This value is called the electronic charge. Protons and neutrons have essentially Charges are usually expressed as multiples of this, the same mass (relative mass 1 u). The rather than as coulombs. mass of an electron is so small we ignore it (relative mass 0 u). Charge of an electron is -1 Charge of a proton is +1 Protons and neutrons are found in the Neutrons are electrically neutral nucleus; electrons travel around the (which is how they got their name). nucleus. Every atom has an equal number of electrons and protons, so atoms have no net electrical charge. Emeka Udenze (https://commons.wikimedia.org/wiki/File:Periodic_Table-1.png), „Periodic Table-1“, https://creativecommons.org/licenses/by-sa/4.0/legalcode Christinelmiller (https://commons.wikimedia.org/wiki/File:Subatomic_Attitude.png), „Subatomic Attitude“, https://creativecommons.org/licenses/by-sa/4.0/legalcode What does the information in each box tell us? 6 Atomic Number = # of protons C Identity Element Symbol Elements are represented by a one or two letter symbol, for which the first letter is always capitalized. Carbon C is the symbol for carbon. Element Name 12.011 Atomic Mass (Atomic Weight) (Mass Number) (Nucleus) On the Periodic table, elements are listed according to their atomic numbers  Number of protons → identity of an atom Can you spot gold (Au)? How many protons does gold have? Eunice Laurent (https://commons.wikimedia.org/wiki/File:Periodic_table_of_elements.png), Only gold has 79 protons https://creativecommons.org/licenses/by-sa/4.0/legalcode What does the information in each box tell us? 6 Atomic Number = # of protons C Atoms have no net electrical charge, they are neutral. Carbon So, the number of protons in a neutral atom must be equal to the number of electrons 12.011 Carbon atom: 6 protons 6 electons (neutral) What does the information in each box tell us? 6 Atomic Number = # of protons C Identity Element Symbol Carbon Element Name 12.011 Atomic Mass (Atomic Weight) = actual mass of the atom (Nucleus) *if you round to the nearest whole number, it is equal to (# of protons + neutrons) What does the information in each box tell us? 6 Atomic Number = # of protons C Atoms have no net electrical charge, they are neutral. So, the number of protons in a neutral atom must be equal to the number of electrons Carbon Carbon atom: 6 protons 12 6 electons (neutral) Atomic Mass = # of protons + neutrons (rounded to the nearest whole number) 12 = 6 + n n=6 6 neutrons C → Atomic Mass: 12.011 → Why is this a decimal number? Isotopes: Atoms of the same element (have same number of protons) with different atomic masses due to different number of neutrons. 31  Isotopes Atomic mass of isotope (p + n) 12 13 14 6 C 6 C 6 C Isotope notation: Atomic number Carbon-12 Carbon-13 Carbon-14 6 protons 6 protons 6 protons 6 electrons 6 electrons 6 electrons 6 neutrons 7 neutrons 8 neutrons Isotopes 1 Hydrogen has three naturally occuring isotopes: H 1.008 Hydrogen Deuterium Tritium 1p 1p 1p 3 1 H 2 H H 1 e- 1 e- 1 e- 1 1 1 0n 1n 2n 33  Atomic Mass & Atomis Mass Unit (u) (amu) Atoms have extremely small masses. Atomic mass is the mass of an atom in atomic mass units (amu) or (u). 1 atom 12 C “weighs” 12 amu The masses of any atom is compared to C-12 (6 protons and 6 neutrons) being exactly 12. The heaviest known atoms have a mass of approximately 4 × 10–22 g. A mass scale on the atomic level is used, where an atomic mass unit (u) is the base unit. 1 u = 1.66054 × 10–24 g Micro World Macro World → atoms & molecules grams  Isotopes & Average (Relative) Atomic Mass – Atomic Weight In nature, isotopes exist in different abundancies. 12 13 14 C C C Carbon-12 Carbon-13 Carbon-14 Percent abundance: ~98.89% ~ 1.11% Trace amount 6 «Average atomic mass» of an element. Calculated according to the mass and percent abundance of each C isotope of that element. This is the element’s atomic weight. 12.011 12Chas the highest abundancy, but the others also affect the average mass value Atomic Weight Measurement Atomic and molecular weight can be measured using a mass spectrometer: The spectrum of chlorine showing two isotopes. Abundances can also be determined this way. Fractional Abundance and Average Atomic Mass Example: Chlorine (Cl) is has two isotopes: chlorine-35 (35Cl) and chlorine-37 (37Cl). ~ 75.78% of all chlorine atoms are 35Cl with a mass of 34.969 amu the remaining 24.22% are 37Cl with a mass of 36.966 amu. amu (u): atomic mass unit How to calculate the average atomic mass of chlorine? Mass spectrum 35Cl 75.78% (Cl has 17 protons) 37Cl 24.22% 37 Fractional Abundance and Average Atomic Mass The average atomic mass = the sum of each individual isotope’s mass multiplied by its fractional abundance. 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 = 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 𝑜𝑜𝑜𝑜 𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 × 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝑜𝑜𝑜𝑜 𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 𝑖𝑖 (atomic weight) 𝑖𝑖 35Cl 75.78 : 75.78 % 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑜𝑜𝑜𝑜 35𝐶𝐶𝐶𝐶 = = 0.7578 35Cl mass: 34.969 amu 100 24.22 37Cl : 24.22 % 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑜𝑜𝑜𝑜 37𝐶𝐶𝐶𝐶 = = 0.2422 37Cl mass: 36.966 amu 100 Average atomic mass of chlorine = (0.7578 x 34.969 amu) + (0.2422 x 36.966 amu) (atomic weight) =35.45 amu (u) 38  Eunice Laurent (https://commons.wikimedia.org/wiki/File:Periodic_table_of_elements.png), https://creativecommons.org/licenses/by-sa/4.0/legalcode Periodic table organizes elements according to their physical and chemical properties. Elements are arranged in order of increasing atomic number (proton number). Organization of the Periodic Table Groups (columns) and periods (rows) form the periodic table. Elements in the same group have similar chemical properties. Periodicity Upon inspection of chemical properties of elements, a repeating pattern of properties and reactivity can be detected.  Group 1: Alkali metals Group 2: Alkaline earth metals Group 16: Chalcogens Group 17: Halogens Eunice Laurent (https://commons.wikimedia.org/wiki/File:Periodic_table_of_elements.png), https://creativecommons.org/licenses/by-sa/4.0/legalcode Group 18: Noble gases Periodic Table Metals On the left side of the periodic table. Individual properties of metals vary. General Properties: Conductive, can conduct electricity and heat quite well Shiny in appearance (metallic!) Can be molded or re-shaped, can bend without shattering. o Malleable: most metals can be hammered into thin sheets o Ductile: able to be stretched or drawn into wire Solids at room temperature, except mercury (Hg) Periodic Table Nonmetals On the right side of the periodic table. Hydrogen is the only nonmetal on the left side. Individual properties of nonmetals vary. General Properties: Usually poor conductors of heat and electricity Not shiny, not malleable, not ductile Can be solid (C), liquid (Br), or gas (Ne) at room temperature. Brittle when solid Periodic Table Metalloids Elements on the steplike line are metalloids (except Al, Po, and At). Have properties of both metals and non-metals, display mixed properties Most common metalloid is Silicon, the second most common element in the Earth’s crust. Si, semiconductive, used in electronics Eunice Laurent (https://commons.wikimedia.org/wiki/File:Periodic_table_of_elements.png), https://creativecommons.org/licenses/by-sa/4.0/legalcode  Example What is the name and isotope notation of a Bromine isotope with 47 neutrons? Atomic mass of isotope Isotope notation Br Atomic number (p) Atomic mass of isotope = (p + n) 82 82 Br 35 Br Br 35 = 35 + 47 = 82 Bromine 82 Example Give the number of protons (p), neutrons (n), and electrons (e) in each of the following species: ( a ) 2011Na (b ) 2211Na ( ) O c 17 a) 20 11 Na Atomic number = 11 → 11 protons → 11 electrons (neutral) Atomic mass = 20 = protons + neutrons 20-11 → 9 neutrons b) 22 11 Na Atomic number = 11 → 11 protons → 11 electrons (neutral) Atomic mass = 22= protons + neutrons neutrons= 22-11 = → 11 neutrons ( a ) 2011 Na and (b) 22 11 Na → isotopes c) 17 O Atomic number is not given, but can be found from any periodic table! Atomic number of Oxygen : 8 → 8 protons → 8 electrons (neutral) Atomic mass = 17 = protons + neutrons neutrons= 17- 8 → 9 neutrons Chemical Formulas The subscript to the right of the symbol of an element tells the number of atoms of that element in one molecule of the compound. Molecular compounds are composed of molecules and almost always contain only nonmetals. Glucose C6H12O6  Chemical Formulas –Monoatomic, Diatomic, Polyatomic Some elements are composed of units that consist of pairs of atoms. These units are called molecules. In nature, the elements hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine and iodine exist as diatomic molecules, in their purest form. H2 N2 O2 F2 Cl2 Br2 I2 Two H atoms are Two O atoms are bonded to each bonded to each H2 other. O2 other.  Chemical Formulas –Monoatomic, Diatomic, Polyatomic These diatomic elements occur in nature in the form of two atoms of the same element bonded by covalent bonds. Elements exisiting as polyatomic molecules are also present. https://wou.edu/chemistry/courses/online-chemistry-textbooks/ch150-preparatory-chemistry/ch150-chapter-4-covalent-bonds-molecular-compounds/ Types of Formulas Empirical formulas give the lowest Molecular formulas give the exact whole-number ratio of atoms of number of atoms of each element in each element in a compound. a compound. If we know the molecular formula of a compound, we can determine its empirical formula. The converse is not true without more information! Picturing Molecules Structural formulas show the Perspective drawings, ball-and-stick models, order in which atoms are attached. and space-filling models show the 3D order They do NOT depict the 3D shape of the atoms in a compound. of molecules.  Ions An ion is an atom, or group of atoms, that has a net positive or negative charge. cation – ion with a positive charge If a neutral atom loses one or more electrons it becomes a cation. anion – ion with a negative charge If a neutral atom gains one or more electrons it becomes an anion. The periodic table can be used to predict if an atom will become an anion or a cation. 57  Ions Cations are formed when at least one electron is lost. Monatomic cations are formed by metals. (Metal atoms tend to lose electrons) Anions are formed when at least one electron is gained. Monatomic anions are formed by nonmetals, except the noble gases. (Nonmetal atoms tend to gain electrons)  Ions An ion is an atom, or group of atoms, that has a net positive or negative charge. cation – ion with a positive charge If a neutral atom loses one or more electrons it becomes a cation. Na 11 protons Na + 11 protons 11 electrons 10 electrons anion – ion with a negative charge If a neutral atom gains one or more electrons it becomes an anion. Cl 17 protons Cl - 17 protons 17 electrons 18 electrons 59 Example 16 Atomic number = 8 → 8 protons 8 O → 8 electrons (neutral) Atomic mass = 16 neutrons = Atomic mass – protons = 16 - 8 → 8 neutrons Solution: Atomic number = 8 → 8 protons 16 2- Charge: -2 (2 electrons gained) 8 O an anion → 8 + 2 = 10 electrons Atomic mass = 16 neutrons = Atomic mass – p n= 16 – 8 = 8 neutrons 60 Example What is the net charge of Chromium (Cr) with 22 electrons? Let’s find Chromium on the Periodic table. How many protons does Cr have? 24 protons A neutral Cr would have 24 electrons So if there are 22 electrons and 24 protons? +2 Has a net (+2) charge Cr Cation Has lost 2 electrons Polyatomic Ions Sometimes a group of atoms will gain or lose electrons. These are polyatomic ions. Ammonium ≡ NH4+ Sulfate ≡ SO42– Hydronium ≡ H3O+ Phosphate ≡ PO43– polyatomic cations polyatomic anions Common Cations name of a metal ion = name of the metal atom from which it forms. If a metal can form cations with different charges: -> the positive charge is indicated by a Roman numeral in parentheses following the name of the metal.  Common Anions name of a nonmetal ion = ending of element’s name replaced by the suffix ‘–ide’ Common cations & anions Common polyatomic ions Molecular Compounds Molecular compounds are composed of molecules and almost always contain only nonmetals. Glucose C6H12O6 Ionic Compounds Ionic compounds (such as NaCl) are generally formed between metals and nonmetals. Electrons are transferred from the metal to the nonmetal. The oppositely charged ions attract each other. Only empirical formulas are written. The sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero. Writing Formulas Because compounds are electrically neutral, one can determine the formula of an ionic compound this way: The charge on the cation becomes the subscript on the anion. The charge on the anion becomes the subscript on the cation. If these subscripts are not in the lowest whole-number ratio, divide them by the greatest common factor. Chemical Nomenclature The system of naming compounds is called chemical nomenclature. We will learn how to name: o Ionic compounds o Acids o Binary Molecular Compounds o Simple Organic Compounds Alkanes Alcohols Inorganic Nomenclature Write the name of the cation. If the cation can have more than one possible charge, write the charge as a Roman numeral in parentheses. If it is a polyatomic cation, it will end in -ium. If the anion is an element, change its ending to -ide; if the anion is a polyatomic ion, simply write the name of the polyatomic ion. Patterns in Oxyanion Nomenclature When there are two oxyanions involving the same element: Central atoms on the second row have a bond to, at most, three oxygens; those on the third row take up to four. Charges increase as you go from right to left. Patterns in Oxyanion Nomenclature The one with the fewest oxygens has the prefix hypo- and ends in -ite: ClO– is hypochlorite. The one with the second fewest oxygens ends in -ite: ClO2– is chlorite. The one with the most oxygens has the prefix per- and ends in -ate: ClO4– is perchlorate. The one with the second most oxygens ends in -ate: ClO3– is chlorate.  Acid Nomenclature If the anion in the acid ends in -ide, change the ending to -ic acid and add the prefix hydro-. HCl: hydrochloric acid HBr: hydrobromic acid HI: hydroiodic acid If the anion ends in -ate, change the ending to -ic acid. HClO3: chloric acid HClO4: perchloric acid If the anion ends in -ite, change the ending to -ous acid. HClO: hypochlorous acid HClO2: chlorous acid Nomenclature of Binary Compounds The name of the element farther to the left in the periodic table (closer to the metals) or lower in the same group is usually written first. A prefix is used to denote the number of atoms of each element in the compound (mono- is not used on the first element listed, however). Nomenclature of Binary Compounds The ending on the second element is changed to -ide. CO2: carbon dioxide CCl4: carbon tetrachloride If the prefix ends with a or o and the name N2O5: dinitrogen pentoxide of the element begins with a vowel, the two CO: carbon monoxide successive vowels are often elided into one. Nomenclature of Binary Compounds OF2 oxygen difluoride Cl2O8 dichlorine octoxide SO3 sulfur trioxide nitrogen trifluoride NF3 disulfur dichloride S2Cl2 dinitrogen tetroxide N2O4 Nomenclature of Organic Compounds: Alkanes Organic chemistry is the study of carbon. Organic chemistry has its own system of nomenclature. The simplest hydrocarbons (compounds containing only carbon and hydrogen) are alkanes. The first part of the names just listed correspond to the number of carbons (meth- = 1, eth- = 2, prop- = 3, etc.). It is followed by -ane. Nomenclature of Organic Compounds: Alcohols When a hydrogen in an alkane is replaced with something else (a functional group, like –OH in the compounds below), the name is derived from the name of the alkane. The ending denotes the type of compound. -> An alcohol ends in -ol. Nomenclature of Organic Compounds: Alcohols When two or more molecules have the same chemical formula, but different structures, they are called isomers. 1-Propanol and 2- propanol have the oxygen atom connected to different carbon atoms, but both have the formula C3H8O. References Chemistry, The Central Science, 15th edition, By Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, Catherine, J. Murphy, Patrick M. Woodward, Matthew W. Stoltzfus, Pearson Press, USA (9781292407586-Mastering Chemistry Brown Chemistry GE 15e) Chemistry, 13th Edition by Raymond Chang, Jason Overby, McGraw-Hill (2019)