General Chemistry 1 PDF
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This document covers general chemistry topics like matter, its properties, and different states of matter. It also touches upon important concepts like Bose-Einstein Condensate (BEC) and its applications. The text is likely from a textbook or study guide.
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GEN CHEM STEM REVIEWER BY ABBCCHPS GENERAL CHEMISTRY 1 LESSON 1: MATTER AND ITS PROPERTIES MATTER BOSE-EINSTEIN CONDENSATE...
GEN CHEM STEM REVIEWER BY ABBCCHPS GENERAL CHEMISTRY 1 LESSON 1: MATTER AND ITS PROPERTIES MATTER BOSE-EINSTEIN CONDENSATE BEC (Bose-Einstein Condensate) -a state of matter - anything that has mass and occupies space. that consists of a collection of atoms near absolute zero; Everything on earth has mass and takes up space. all the atoms have that lowest possible quantum energy Kinetic Particle Theory- states that matter is state. particularly in nature. PARTICLES COMPOSING MATTER Atoms- these are the smallest unit of matter that can’t be broken chemically. MOLECULES - These are groups of two or more atoms that are chemically bonded. IONS- These are particles that have gained or lost one or more of their valence electrons. STATES OF MATTER SOLID - fixed shape but has fixed volume. No spaces. Arrangement is regular. Speed is slow. Force attraction is strong. LIQUID - no fixed shape but has fixed volume. Have some spaces. Arrangement is random. Speed is medium. Force attraction less than solid more than gas. GAS - no fixed shape and volume. Particles are spread out. Arrangement is random. Speed is Fast. Force attraction is very weak. PLASMA - consist of charged particles, plasma has 1. Superfluid helium-4 innate electrical conductivity and a magnetic field. most Superfluid helium-4 is a type of BEC that is made up of plasma is electrically neutral. helium-4 atoms. It is a very cold liquid that flows without However, there can be regions of current density that friction. Superfluid helium-4 is used in a variety of form filaments (visible in a plasma ball or aurora) or magnetic ropes. Also, there is non-neutral plasma that applications, such as cryogenics and medical imaging. consists entirely of a single charge (e.g., particle beams or the electrons in a Penning trap). 2. Superconducting materials Examples Superconducting materials are made up of atoms that Lightning can form BECs. When these materials are cooled to a Aurora very low temperature, they lose all electrical resistance. Comet tail Solar wind Superconducting materials are used in a variety of Stars (including the Sun) applications, such as MRI machines and particle Interstellar gas clouds accelerators. Welding arcs Interior of neon signs and fluorescent lights 3. Lasers Interior of a plasma ball toy Lasers are made up of photons that are all in the same Static electricity quantum state. This is achieved by stimulating the Fireball of a nuclear explosion Earth's ionosphere emission of photons from a BEC. Lasers are used in a Earth's magnetosphere variety of applications, such as telecommunications and Plasma displays of some televisions surgery. Rocket exhaust and thrusters Area in front of a heat shield during spacecraft re-entry 4. Atomic clocks Interstellar nebula Atomic clocks are based on the fact that the frequency of Interstellar and intergalactic medium light emitted by atoms depends on their temperature. By St. Elmo's fire Fire (if it is hot enough) cooling atoms to a very low temperature, their frequency GENERAL CHEMISTRY 1 1 GEN CHEM STEM REVIEWER BY ABBCCHPS can be precisely controlled. Atomic clocks are used in a variety of applications, such as navigation and telecommunications. 5. Quantum information processing Quantum information processing is a field of study that is concerned with the development of new technologies that exploit the properties of quantum mechanics. BECs are being explored as a possible platform for quantum information processing, as they can be used to store and manipulate quantum information. 6. Cosmology BECs are thought to play a role in the early universe. In the early universe, the temperature was very high, and PROPERTIES OF MATTER all particles were in a state of BEC. As the universe expanded and cooled, the particles condensed out of the According to changes involved during measurements of BEC and formed the stars and galaxies that we see the property. today. PHYSICAL PROPERTIES - These can be measured and observed without 7. Neutron stars changing the composition of the substance. Neutron stars are very dense stars that are made up of CHEMICAL PROPERTIES neutrons. The neutrons in neutron stars are thought to - These are the ability of a substance to react with form a BEC. This BEC gives neutron stars their unique other substances such as air, water, and base. properties, such as their strong magnetic fields and their ability to emit gravitational waves. According to dependence on the amount of matter INTENSIVE PROPERTIES 8. Dark matter - It does not depend on the size or amount of the Dark matter is a mysterious substance that makes up sample. about 85% of the matter in the universe. Dark matter is EXTENSIVE PROPERTIES thought to be made up of weakly interacting massive - These can be affected by the size and amount of particles (WIMPs). Some scientists believe that WIMPs samples. could form BECs. PHYSICAL PROPERTIES 9. Quark-gluon plasma INTENSIVE PHYSICAL EXTENSIVE PHYSICAL Quark-gluon plasma is a state of matter that is thought to PROPERTIES PROPERTIES have existed in the early universe. It is made up of quarks and gluons, which are the fundamental particles of matter. Quark-gluon plasma is a very hot and dense -Color -Mass state of matter, and it is thought to be a BEC. -Melting Point -Volume -Density -Length 10. Quantum computers -Solubility Quantum computers are a type of computer that uses -Conductivity the principles of quantum mechanics to perform -Malleability calculations. BECs are being explored as a possible -Luster platform for quantum computers, as they can be used to -Viscosity store and manipulate quantum information. -Bolling Point -Temperature -Odor GENERAL CHEMISTRY 1 2 GEN CHEM STEM REVIEWER BY ABBCCHPS CHEMICAL PROPERTIES 1. Combustibility - Whether the substance undergoes Filtration or Sedimentation - The most common combustion or not method of separating a liquid from an insoluble solid is 2. Stability - Whether the substance can be easily the filtration. Take, for example, the mixture of sand and decomposed or not water. Filtration is used here to remove solid particles 3. Reactivity -Whether it reacts with acids, bases, and from the liquid. Various filtering agents are normally used oxygen, gas or not like filtering paper or other materials. 4. Relative Activity - Whether the material is more active or less active than other members of its chemical Sedimentation - is a process by which heavier family impurities present in liquid normally water settle down at 5. Lonization - Whether it will break into charged the bottom of the container containing the mixture. The particles when in solution with water or not. process takes some amount of time. 6. Toxicity - Whether substance can damage an organism or not. Decanting - To pour off a liquid, leaving another liquid or solid behind.Takes advantage of differences in density. Example: To decant a liquid from a precipitate or water METHODS OF SEPARATING MIXTURE from rice. Handpicking - This method involves simply picking out all unwanted substances by hand. Separating Funnel - Separating funnel is used mainly to segregate two immiscible liquids. The mechanism Threshing - This method is mostly done during the involves taking advantage of the unequal density of the harvesting of crops. Normally, the stalks of the wheat are particles in the mixture. Oil and water can be easily dried once it is harvested.The grain is then separated separated using this technique. from the stalks and grounded into the floor by `beating the dry stalks to shake off the dried grains. Magnetic Separation - When one substance in the mixture has some magnetic properties then this method Winnowing - When the grains are collected from the is quite useful. Strong magnets are commonly used to process of threshing, it needs to be cleared out of husks separate magnetic elements. and chaffs before it is turned flour. Normally, the separation of the mixture is carriewd out with the help of Centrifuge:Circular motion helps denser components wind or blowing air. The husk and chaff are blown about sink to the bottom faster. by the stong wind when the farmers drop the mixture Example: The separation of blood or DNA from blood from a certain height to the ground. The heavier grains are collected at one place Paper chromatography: Uses the property of molecular attraction (molecular Sieving - It is done to separate mixtures that contain polarity) to separate a mixture. substances mostly of different sizes. The mixture is Different molecules have varying molecular attractions passed through the pores of the sieve. All the smaller for the paper (the stationary phase) substances pass through easily while the bigger vs. the solvent (the mobile phase) components of the mixture are retained. Example: the separation of plant pigments and dye Evaporation - Evaporation is a technique that is used in Fractional Crystallization: separating a mixture, usually a solution of a solvent and Dissolved substances a soluble solid. In this method, the solution is heated crystallize out of a solution once their solubility limit is until the organic solvent evaporates where it turns into a reached as the solution cools. gas and mostly leaves behind the solid residue. Examples: Growing Rock Candy or the Crystallization of a Magma Chamber Distillation - When mixtures consist of two or more pure liquids than distillation is used. Here the components of a liquid mixture are vaporized, condensed and then isolated. The mixture is heated and the component which is volatile evaporates first. The vapour moves through a condenser and is collected in a liquid state. GENERAL CHEMISTRY 1 3 GEN CHEM STEM REVIEWER BY ABBCCHPS LESSON 2: SCIENTIFIC MEASUREMENTS Measurements can be either qualitative or quantitative. Quantitative can be checked using accuracy or precision expressed in number of significant figures which can be expressed in scientific notation Qualitative measurement are descriptive. e.g. heavy, hot, and bright Quantitative measurements are numeric in nature and depend on : a.measuring instrument b.the care with which it is read. A number is followed by a unit When you take a measurement, you always MASS AND WEIGHT compare it with a reference standard. International System of Units (SI) Mass - the amount of matter in an object. was established in 1960 by the General Conference on - unit of mass is gram (g) or kilogram (kg) Weights and Measures. derived from the French name, - constant Le Systeme International d'Unites built upon a set of seven metric units called the base units. Weight - equal to the force of gravity on the object. - unit of mass is Newton (N) - varies with location Why do people say weight instead of mass? People often use the term "weight" instead of "mass" because it's more intuitive for everyday situations. 1. Everyday Context: In everyday language, weight is what we usually refer to when talking about how heavy something feels or how much it weighs on a scale. For example, when you say you weigh 150 pounds, you're actually talking about your weight, which is a measure of the force exerted by gravity on your mass. 2. Measurement Tools: Most scales measure weight, not mass. They provide a reading based on how much force the object exerts on the scale due to gravity. This force is then translated into a weight reading. 3. Common Usage: In many practical situations, like cooking or shipping, we use weight as the relevant measure. For instance, recipes are often written with weights for ingredients. 4. Mass vs. Weight: Scientifically, mass is the amount of matter in an object and is constant regardless of location. GENERAL CHEMISTRY 1 4 GEN CHEM STEM REVIEWER BY ABBCCHPS Weight, however, is the force exerted by gravity on that mass and can vary depending on where you are (e.g., on the Moon DERIVED UNITS vs. on Earth). Despite this, in everyday conversation, the are the combination of' units. distinction between mass and weight isn't always necessary or Ex: Speed is defined as the distance divided by the time practical. required traveling that distance. Thus, the SI unit for So, while scientists make a clear distinction between mass and speed is meter per second (m/s). weight, in everyday language, weight is often used because it's what people experience and measure in their daily lives. Volume has different units: = cubic meters (m') or cubic centimeters (cm') TEMPERATURE = Liter (L) or milliliters (mL) measure of how hot or cold an object is measured with a thermometer. Heat moves from the object at the higher The space occupied by any sample of matter. temperature to the object at the lower temperature. Calculated for a solid by multiplying the length x 3 units used: width x height; thus derived from units of length. Celsius (°C) - named after Anders Sl unit = cubic meter (m?) Celsius Kelvin (K) - named after William Everyday unit = Liter (L), which is non-Sl. Lord Kelvin Fahrenheit (°F) - named after Daniel (Note: 1mL = 1cm') Gabriel Fahrenheit DEVICES FOR MEASURING LIQUID VOLUME Celsius scale Graduated cylinders Freezing point of water = 0°C Pipets Boiling point of water = 100 °C Burets Volumetric Flasks Kelvin scale Syringes Freezing point of water = 273 K Boiling point of water = 373 K The zero point on the Kelvin scale (0 K), is called the DENSITY absolute zero temperature and is equal to -273 °C. is defined as the amount of mass of an object divided by its volume. Fahrenheit scale density = mass Freezing point of water = 32°F volume Boiling point of water = 212 °F d= M V Units used: liquid = g/mL solid = kg/m' or g/cm3 EXAMPLE: The normal body temperature is 37°C. What is this in a Fahrenheit thermometer? Solution: T°F= 9/5 T°C +32 = 9/5 (37°C) +32 = 66.6+32 T°F= 98.6°F GENERAL CHEMISTRY 1 5 GEN CHEM STEM REVIEWER BY ABBCCHPS EXAMPLE RULES FOR COUNTING SIGNIFICANT FIGURES Leading Zeros do not count as significant figures: 0.0486 has 3 significant figures Captive Zeros always count as significant figures: 16.07 has 4 significant figures Trailing Zeros are significant only if the number contains a written decimal point: 9.300 has 4 significant figures Non-zeros always count as significant figures: 3456 has 4 significant figures Two special situations have an unlimited number of significant figures: 1. Counted items a) 23 people, or 425 thumbtacks SIGNIFICANT FIGURES 2. Exactly defined quantities In measurements there is always some amount b) 60 minutes = 1 hour of uncertainty What are significant digits? - The significant digits in a measurement consist of all digits known with certainty plus one final digit, which is uncertain or is estimated. Why Is there Uncertainty? Measurements are performed with instruments, and no instrument can read to an infinite number of decimal places Which of the balances below has the greatest uncertainty in measurement? Repeating a particular measurement will usually not obtain precisely the same result. The measured values vary slightly from one another. It is necessary to make good, reliable measurements in the lab Accuracy - how close a measurement is to the true value Precision - how close the measurements are to each other (reproducibility). SIGNIFICANT FIGURES IN MEASUREMENTS Significant figures in a measurement include all of the digits that are known, plus one more digit that is estimated. Measurements must be reported to the correct number of significant figures. GENERAL CHEMISTRY 1 6 GEN CHEM STEM REVIEWER BY ABBCCHPS DIMENSIONAL ANALYSIS Dimensional analysis relates similar measurements to different units through a conversion factor - Also known as Factor - Label Method SCIENTIFIC NOTATION - is a form of presenting very large numbers or very small numbers in a simpler form. GENERAL CHEMISTRY 1 7 GEN CHEM STEM REVIEWER BY ABBCCHPS LESSON 3: ATOMS, MOLECULES, AND COMPOUNDS ATOM STRUCTURE OF THE ATOM Democritus:Atomos 400BC- Atom - smallest particle of an element that can exist Atoms are the building blocks of matter, the shape of an alone atom explain elements behavior. Two regions of an atom Nucleus John Dalton: Solid Sphere 1803- Atom is a Center of atom solid indivisible sphere. _ Protons and neutrons J.J. Thomson: Plum Pudding 1897- Negative Electron "cloud" electrons are embedded in a sea of positive Area surrounding nucleus charges. containing electrons Ernest Rutherford:Nuclear 1911- Positive charges are located within a central nucleus. Niels Bohr:Planetary 1913- Electrons are restricted in circular orbits with different energy levels. Erwin Schrödinger: Quantum 1926- Electrons Proton - Positive charge (+), 1 atomic are in clouds surrounding the nucleus, and this mass unit (amu); found in the nucleus cloud is less dense. amu -Approximate mass of a proton or a neutron Neutron - Neutral charge (0), 1 amu; found in the DALTON'S ATOMIC THEORY nucleus Electron - Negative charge (-), mass is VERY small All matter is made of atoms. All atoms of a given element are identical in mass and ATOMIC NUMBER properties. The atoms of a given element are different from those Number of protons in nucleus of any other element. The number of protons determines identity of the Compounds are combinations of two or more different element types of atoms. A chemical is a rearrangement of atoms. ATOMIC MASS (MASS NUMBER) Number of protons + neutrons THREE LAWS THAT LED TO ATOMIC Units are g/mol THEORY Law of Mass Conservation: The total mass of substances does not change during a chemical reaction (Lavoisier). Law of Definite (or Constant) Composition: No matter what its source, a particular chemical compound is ISOTOPES composed of the same elements in the same parts Atoms of the same element with varying number of (fractions) by mass (Proust). neutrons The Law of Multiple Proportions: When two elements Different isotopes have different mass numbers form a series of compounds, the masses of one element because the number of neutrons is different. that combine with a fixed mass of the other element are in the ratio of small integers to each other (Dalton). GENERAL CHEMISTRY 1 8 GEN CHEM STEM REVIEWER BY ABBCCHPS CHEMICAL NAMES AND FORMULAS A chemical formula indicates the elements and their proportions in a compound. TYPES OF MOLECULE Monatomic - made of only one atom Diatomic molecules — a molecule containing only two atoms Molecular Formula- The molecular formula of an Polyatomic Molecules - a molecule containing more organic compound simply shows the number of each than two atoms type of atom present. It tells you nothing about the bonding within the compound. Empirical formula- The empirical formula of an organic compound gives the simplest possible whole number ratio of the different types of atom within the compound. Condensed formula- In condensed formulae, each carbon atom is listed separately, with atoms attached to it following. In cyclic parts of molecules, like benzene, carbons are grouped Displayed formula A displayed formula shows all of the atoms and all of the bonds present in an organic compound. The bonds are represented as lines. GENERAL CHEMISTRY 1 9 GEN CHEM STEM REVIEWER BY ABBCCHPS Structural Formula- Similar to displayed formula; not all bonds are shown, although all atoms are still indicated COMMON SIMPLE OF CATION AND ANION using subscript numbers. Carbon hydrogen bonds are often simplified. Skeletal Formula- In skeletal formulae, most hydrogen atoms are omitted. Line ends or vertices represent carbons. Functional Groups and atoms other than carbon or hydrogen are still shown. RULES FOR NAMING TYPE I IONIC NAMING COMPOUNDS COMPOUNDS Binary Compounds Compounds -Composed of two elements 1. The cation is always named first and the anion Binary lonic Compounds second. -Metal-nonmetal 2. A simple cation takes its name from the name of the Binary Covalent Compounds element. - Nonmetal-nonmetal 3. A simple anion is named by taking the first part of the Binary ionic compounds contain positive cations and element name (the root) and adding -ide. negative anions. Type I compounds -Metal present forms only one cation. Type Il compounds -Metal present can form 2 or more cations with different charges. Binary lonic Compounds (Type I) Examples: KCI - Potassium chloride MgBr2 (Yung maliit na two sa baba)- Magnesium bromide CaO - Calcium oxide Binary ionic Compounds (Type II) Metals in these compounds can form more than one type of positive charge. Charge on the metal ion must be specified. Roman numerals indicate the charge of the metal cation. Transition metal cations usually require a Roman numeral. GENERAL CHEMISTRY 1 10 GEN CHEM STEM REVIEWER BY ABBCCHPS Binary lonic Compounds (Type II) Examples: CuBr - Copper(I) bromide FeS - Iron(Il) sulfide PbO2(Yung maliit na two sa baba) -Lead(IV) oxide Rules for Naming Type III Binary Compounds Formed between two nonmetals. 1. The first element in the formula is named first, and the full element name is used. 2. The second element is named as though it were an anion. 3. Prefixes are used to denote the numbers of atoms present. 4. The prefix mono- is never used for naming the first element. Type III Compounds Non-Metals and Non-Metals Common Type Il Cations Use Prefixes such as mono, di, tri, tetra, penta, hexa, hepta, etc. CO, Carbon dioxide - CO Carbon monoxide PCI Phosphorus trichloride CCI, Carbon tetrachloride N2(small 2 ulit) O2(small 2 ulit), Dinitrogen pentoxide CS, Carbon disulfide Rules for Naming Type Il lonic Compounds Binary Covalent Compounds (Type III) 1. The cation is always named first and the anion second Examples: 2. Because the cation can assume more than one COr - Carbon dioxide charge, the charge is specified by a Roman SF6 - Sulfur hexafluoride numeral in parentheses. N2O2(small 2 ulit)-Dinitrogen tetroxide GENERAL CHEMISTRY 1 11 GEN CHEM STEM REVIEWER BY ABBCCHPS FLOW CHART OF NAMING BINARY COMPOUNDS OVERALL STRATEGY OF NAMING CHEMICAL COMPOUNDS GENERAL CHEMISTRY 1 12