GChem-1-Lessons-1-20.pdf

General Chemistry 1 (First Quarter) Lesson 1: The Particulate Nature of Matter Lesson 3: Physical and Chemical Properties Matter - Any material that has mass and occupies space. Properties of Matter – can be classified based on the - Ma...

General Chemistry 1 (First Quarter) Lesson 1: The Particulate Nature of Matter Lesson 3: Physical and Chemical Properties Matter - Any material that has mass and occupies space. Properties of Matter – can be classified based on the - Made up of atoms. changes that occur while observing or measuring these properties: Atoms - Tiny indivisible building blocks. - The size of each can be expressed in angstrom (Å), Physical Properties – observed or measured without which is 1/10^10 of a meter. producing a new substance. - Tiny that cannot be seen by naked eye. Boiling Point – temperature at which liquid boils and - Can be viewed by Scanning Tunneling Microscope becomes gas. (STM). Melting Point – temperature at which a solid melts and become liquid. Atom Types - 118 different types reported. Phase Change – change in physical state of a - Some are naturally occurring; some are artificially substance. In this, no new substance is changed. prepared. Hardness Monoatomic Substances - One-atom substances. - Example: helium – used in filling balloons. Molecules - When two or more atoms combine. Diatomic Molecules – some are diatomic by nature. - Some are made up of only one atom type and some are with 2 different atom types. - Example: oxygen gas – 2 oxygen atoms. Hydrogen fluoride gas – composed of one hydrogen & one fluorine atoms. Polyatomic Molecules – some are made up of 3 or more Chemical Properties – properties that are observed or atoms of different types. measured with accompanying chemical reactions, leading to - Example: ammonia, carbon dioxide, water. change in the identity or composition of a substance. Flammability – ability of substance to burn. Atomic Arrangements in a Molecule Toxicity – ability to poison or cause harm to an - Changing the order by which atoms are arranged in organism. substance results in the formation of new substance. o Interferes with chemical processes occurring in one’s body in a harmful way. Ions – atoms or a group of atoms with a net positive or o The lesser amount of a substance needed to negative charge. harm a given mass of organism, the more toxic it is. Cation – positive net charge. Lesson 4: Intensive and Extensive Properties Anion – negative net charge. Properties of matter can be classified based on how size or amount affect them: Lesson 2: Sates of Matter Solid – has its own definite shape and volume. Extensive Properties – properties that vary depending on - Made up of constituent particles that are positioned in the size or amount of matter. an ordered manner and so close together that they - Additive. barely move. Length – tells us the distance from one position to - Tends to resist compression. another. - Example: iron nail – rigid, owing to the ordered Mass – measure of how atter resists motion. arrangement of iron atoms. o Related to the amount of a substance. Volume – three-dimensional space occupied by an Liquid – has a definite volume but conforms with the shape object. of the container it fills in. Width - Particles making up a liquid is less ordered than solids. Area - Distances among particles are a bit far away and are Energy enough for them to move. - Cannot be compressed significantly like solids. Energy Currency of the Human Body: ATP (Adenosine - Example: water – hydrogen bonds aren’t broke in 0-100 Triphosphate) degrees Celsius temperatures. Intensive Properties – properties that are not affected by Gas – has no definite volume and shape. size or amount of matter. - These properties are due to random arrangement of - Indicative of a substance’s identity. particles that are very far away from each other. - Not additive. - Gas particles can move freely randomly, easily compressed by reducing size of container.  General Chemistry 1 (First Quarter) Temperature – measure of hotness or coldness of an o Decantation - solids are allowed to settle in the object. container before the liquid is slowly poured Boiling point – no matter what quantity of water is off. heated, both will boil at 100 degrees Celsius. Density – mass of an object per unit volume. 5. Magnetic Property – metals (iron, nickel, cobalt) o The object’s mass is divided by its volume. can be attracted by magnets. But gold, silver, and o The greater volume of water has great mass but aluminum are not attracted. the density remains the same since the identity and composition isn’t varied. 6. Size – in mixtures of different substances with o The density of water will change only if significant difference in size, one can manually do another substance is added to it. the separation. Hardness - In baking, we pass flour, sugar, and other solid Ductility ingredients through a strainer to separate fine solids Malleability from the coarse ones (sifting). Color Lesson 6: Formulas of Common Chemical Substances Types of Atoms – there are more than 100 different types of Osmosis – semi-permeable or semi-conservative like our them with each has its unique properties. cell membrane. Diffusion – different concentrations. Chemical Symbol – one or two-letter representation of Lesson 5: Properties of Matter for Identification and elements. Separation of Substances - Must be written with the first letter capitalized. 1. Density – ratio of the mass and volume of an - Letters are derived from English names (C for Carbon, object, can be used to identify substances. Ar for Argon). - Different substances have different densities. - Some are derived from foreign names like Latin or - Been done more than 2000 years ago when Archimedes German (K for potassium from Latin name – kalium; W of Syracuse found out that a crown he tested wasn’t for tungsten from Greek name – wolfram). made of pure gold. Periodic Table of the Elements 2. Thermal Conductivity – property of how a thing - Names and symbols of the elements are listed in an allows heat to travel easily. array. - Metals: good conductor of heat (thermal insulators). - A crude way to assess the extent of thermal conductivity Chemical Formula of a material is by getting the rate of heating. - Indicates the elements and their proportions in a - Can be obtained by getting the temperature change of compound. the material upon heating for a given time interval. - Consists of chemical symbols of the elements present in - Materials with higher rate of heating are better heat a substance with their respective quantities. conductors. Steps in Writing Chemical Formulas 3. Electrical Conductivity – the ease with which a 1. Convert each element to its corresponding symbol. material allows flow of electric current. 2. If there is only one atom for an element, just write the - Ex.: Copper is used in electrical wirings because it’s a symbol as it is, if there are two or more atoms for that atom good conductor of electricity. type, write the number of atoms as a subscript of the - Rubber and plastic are used to insulate the material in symbol. Do the same for other elements. which the current flows. 3. Combine the symbols and their subscript (if applicable), - With the use of a device, this can be measured. The without spacing. measurement can be compared for other substances. REMEMER: 4. Solubility – amount of substance that can be mixed Some formulas make use of with a given amount of liquid at a certain parentheses. temperature to form a mixture that appears as - Notice that oxygen and hydrogen though nothing is added in the liquid. are enclosed in parentheses followed by 2 as a - A preliminary test can be done to check a substance subscript. solubility in water. SUBSCRIPT – indicates that the compound has two - Soluble in water: table salt, sugar, alcohol. units of particles containing oxygen and hydrogen. - Insoluble in water: chalk dust, sand, cooking oil. Example: - Advantages: No – nobelium o Salt can be separated from sand by adding NO – nitrogen monoxide water. Kal(SO4)2*12H20 – potash alu o Filtration can be done, the insoluble matter is [PtCl2(NH3)2] – cisplatin separated with the aid of a porous material (filter paper) while allowing the liquid to pass through it. LIMITATIONS  General Chemistry 1 (First Quarter) There are chemical formulas that represent 2 or more - Oil and water are substances. immiscible with each other, by - Example: using this apparatus, the water is C2H6O – ethyl alcohol & dimethyl ether at the lower layer because it has C6H12O6 – glucose, fructose, galactose, etc. higher density than oil. 1. EMPIRICAL FORMULA - Simplest whole number ratio. 2. MOLECULAR FORMULA Distillation - Number and type of atoms. - Process in which a liquid is heated in a vessel to 3. CONDENSED FORMULA become a gas, then the gas is condensed into liquid - Order and formula of functional groups. upon passing through a cooling tube (condenser). 4. STRUCTURAL FORMULA - Done to separate homogeneous liquid mixtures and - Graphic representation of structure. solid-liquid mixtures. - Distillate: liquid that comes out from the condenser. Lesson 7: Separation Techniques for Mixtures and - Pot residue: mixture remaining in the vessel. Compounds Filtration Sublimation - The insoluble matter is separated from the liquid with - Process when a solid substance is allowed to sublime the aid of a porous material (filter paper), while and the evolved gas is deposited on a cool surface (such allowing the liquid to pass through it. as the base of a flask containing ice or cold water). - Filtrate: separated liquid - Example: iodine with sand, when heated, iodine - Residue: separated materials sublimes and deposited on the coolest vessel while sand remains at the bottom of the container. Decantation - Solids are allowed to settle in the container before the Evaporation decantate is slowly and carefully poured off, leaving the - Involves heating of a mixture in an evaporating dish to residue in the container. cause removal of the liquid substance. - Decantate: liquid being poured off Chromatography Centrifugation - Method in which substances in a solution can be - The process in which a heterogeneous mixture is spun separated by loading the solution on a material that in a machine. stays in place (stationary phase) and allowing a liquid - The spinning causes centrifugal force to the mixture or gas (mobile phase) to carry the substances. causing the residue to settle. The centrifugate can be removed by simple decantation. - Centrifugal force: outward force. - Centrifugate: liquid after the process. Blood – fluid consisting of cells and other particles scattered throughout plasma. By employing this, the scattered materials settle at the bottom, allowing them to be separated from the plasma. Magnetic Separation - As the mobile phase moves along the stationary phase, - Involves the use of a magnet to remove metals from a the loaded substances move at different speed, resulting mixture. in separation. - Chromatography can be employed to separate plant Manual Separation pigments, which contain different colored substances. - Mixtures consisting of substances that are relatively big enough to be separated by manually picking them. Winnowing - When the grains are collected from the process of Sifting threshing, they need to be cleared out of husks and chaff - Process which a mixture is places in a screen or a before it turned to flour. woven material that allows separation of smaller - The separation of mixture is carried out with the help of particles from the bigger granules. wind or blowing air. Separation using a Separatory Funnel Lesson 8: Matter and Its Properties - Separatory Funnel: apparatus used to separate liuids Chemistry In Industry that do not mix (immiscible liquids). - Industrialization uplifts the quality of human existence - The liquid with higher density – lower layer. and also propels nations to higher levels of economic - Lower density – floats. prosperity. - To release the lower layer, the stopper and the stopcock are opened until only the upper layer remains inside the Chemical in Consumer Products separatory funnel. Calorie – energy upon food intake. Food labels – number of calories per serving.  General Chemistry 1 (First Quarter) 2000-calorie daily diet: - Upon administration of a compound containing Iodine- o 5% below – considered low 123, the isotope goes to the thyroid, enabling effective o 20% above – considered high. visualization of the organ. Fortification – additives mixed with some products to Thallium-201 add or improve nutrient content. - used in heart scanning. - Emits gamma waves which when detected by an Lesson 9: Recognize Common Isotopes and Their Uses instrument will provide an image of blood flow going to the heart muscle. Radioactive Isotopes - Lasts only for a relatively short period. Iodine-131 - Emits small ions and high-energy radiation. - A radioactive isotope used in the treatment of - Have different uses and applications. hyperthyroidism. - Hyperthyroidism: a medical condition in which too Radioactive Elements Found Naturally in Earth’s Crust much production of thyroid hormones from the thyroid Uranium gland happens in the body. Thorium o can be caused by Grave’s disease, a disease in - These two slowly change form and produce decay which the thyroid gland is enlarged. products such as radium & radon. - During this process, energy is released. Chemical Reactions Kinetic Isotope Effect DATING - Isotopes are also used in understanding the Carbon Dating nature of chemical reactions. - Process of determining the age of carbon-containing - For example, hydrogen (the one with mass materials from living organisms based on the quantity number) is replaced with deuterium, an of carbon-14, a radioactive isotope of carbon. isotope with mass number =2 to investigate if the speed of a reaction changes upon this Willard Libby substitution. - Created the system of carbon dating in late 140s. - Soon turned into a standard apparatus for archeologists. Food Processing - Libby got the Novel Prize for his work in 1960. Cobalt-60 - emit gamma rays that can be used to sterilize food Radiocarbon Dating Technique products. - Depends on the way that radiocarbon is being made in - Through this technique, bacteria can be killed without the air by the connection of inestimable beams with air affecting the quality of the product. nitrogen. Energy USES OF ISOTOPES Uranium-233 The ratio of C-14 and C-12 (the most abundant Uranium-235 isotopes) in the form of carbon dioxide is constant. Plutonium-239 - Carbon dioxide is taken up by plants which in turn Plutonium-241 eaten by animals. - Used in generating energy (nuclear fuels). - When they die, this ratio decreases. the remaining C-14 - When bombarded with a neutron, lighter atoms with in the specimen is used to calculate its age. accompanying energy (nuclear fission). - The energy released, in the form of heat, is absorbed by Potassium-40 and Argon-40 water, resulting in the generation of steam. The steam - Used to determine the ages of rocks volcanic rocks) and then passes through the turbine, which will be similar materials. responsible for generating electricity. - Process is called potassium-argon dating. - Dating method is useful for materials formed several Lesson 10: Represent Compounds thousand years ago. Chemical Compound - Any substances that is made up of two or more MEDICINE elements which react with one another. The elements Cobalt-60 must be present in fixed ratios. - Man made isotope of cobalt, used in the treatment of - Example: Hydrogen and Oxygen are pure elements and cancer. are gases. - Emits high-energy radiation (gamma ray). - With the use of an instrument, the emitted radiation Types of Chemical Formula targets the tumor without causing harm to healthy 1. Empirical Formula tissues. - Indicates the different types of elements in a molecule and the lowest whole-number ratio of each kind of atom Iodine-123 in the molecule. - Used for thyroid imaging. - Compounds with different molecular formulas can have the same empirical formulas and such substances will have the same percentage composition.  General Chemistry 1 (First Quarter) Acetic Acid (C2H4O2), Formaldehyde (CH2O), and Glucose (C6H12O6), the empirical formula CH2O. Steps to Calculate Empirical Formula 1. Assume the mass to be 100g so the percent becomes grams Both compounds in the figure have 2 carbon atoms, 6 2. Determine the moles of each element hydrogen atoms, and 1 oxygen atom. The difference is in the 3. Determine the mole ratio by dividing each elements way the atoms are bonded. number of moles by the smallest 4. Double to get an integer if they are not all whole Lesson 11: Naming Compounds’ Given Their Formula numbers. IONS Cations – ion in an electrolyzed solution that migrates to the cathode; broadly, a positively charged ion. Anions – ion in an electrolyzed solution that migrates to the anode; broadly, a negatively charged ion. Ionic Compounds without a Transition Metal Ionic Compounds – formed when a metal gives up its electrons to a non-metal. If the compound contains a metal, its ionic. Transition Metal – element with an atomic number of 21 to 30, 39 to 48, or 75 to 80. Compound with any other metal: 1. Metal ion’s name doesn’t change. 2. The non-metal’s name ends in ide. 3. Subscripts do not affect the way we name them. 2. Molecular Formula Example: - Based on an actual molecule of a compound. AlCl3 = aluminum chloride - Gives the exact number of different atoms of an element Na2S = sodium sulfide in a molecule. K2O = potassium oxide - In some cases, the empirical formula and this are MgH2 = magnesium hydride identical. Steps to Calculate Molecular Formula Ionic Bond 1. After you determine the empirical formula, determine its mass. 2. Determine how many times greater the molecular mass is compared to the mass of the empirical formula. 3. Multiply the empirical formula by this number. Name to Formula 4. Structural Formula - Shows the elements in the compound, the exact number of each atom in the compound, and the bonding pattern for the compound. - The electron-dot formula and Lewis formula are examples of structural formulas.  General Chemistry 1 (First Quarter) Polyatomic Ions Covalent Compounds - When metals are bonded to polyatomic ions (consists of - Formed from non-metals that share electrons. 2 or more atoms with 1 overall charge, the same rules - Ther are many sharing possibilities between two non- apply, but you have to learn the names and charges of metals, the formula can’t be guessed unless there’s a common polyatomic ions. naming system that reveals the no. of atoms involved. For this, we use a set of prefixes: Carbon dioxide – CO2, CO – carbon monoxide ANSWER: Technique for Naming Polyatomic Ion Lesson 12: Chemical Reactions and Equations Chemical Reaction - process by which a chemical takes place - A change where a new substance is formed. Chemical Equation - The shorthand way of expressing chemical reaction using numbers, symbols and formula. Ionic Compound with a Transitional Metal The difference here is that we have to specify the charge Two Major Parts: reactants & products of the transition metal ion by using roman numerals. ✓The starting materials Keep in mind that a transitional metal is an element ✓These are the substances that change when it is combined with an atomic no. 21-30, 39-48, 57-80. Metals in group with another substance in a chemical reaction. B). ✓The new substance ✓The substances that result of the chemical reaction Coefficient - number before the symbol or formula of a substance. Subscript - number of atom of the element found in the substance. To go backwards, we need to figure out the charge of the transition metal: Symbols Used in Chemical Equation  General Chemistry 1 (First Quarter) Law of Conservation of Mass - Remember that the aim is to always cancel the given The sum of the masses of the products is always the unit and convert it to the desired unit. same as the sum of the masses of the reactants. States that mass is neither created nor destroyed in any To find the number of moles A needed to produce 6.0mol B: ordinary chemical reaction. To find the number of moles B produced from 8.0 mol A: Mole & Mass Ratios Steps in Balancing Chemical Equation 1. Check for diatomic molecules. Are molecules composed of only two atoms, of either the same or different chemical elements. 2. Check whether the chemical formulas of all the reactants General Steps: and products are correct. Check the total number of atoms of 1. Make sure that the chemical equation for the each element on each side of the equation. reaction is balanced. 3. A polyatomic ion appearing unchanged on both sides of the 2. User molar mass to convert mass to moles, and vice equation is counted as a single unit. versa. 4. Balance the elements one at a time by using coefficients. 3. Use the mole ratio from the balanced chemical Must not attempt to balance the equation by changing the equation to convert moles of the given substance to subscripts in the chemical formula of a substance. moles of another substance. 5. Check each atom or polyatomic ion to be sure that the equation is balanced. Example 1: Copper can be dissolved in nitric acid according to the following reaction: ANSWER: Lesson 13: Construct Mole or Mass Ratios for a Reaction in Order to Calculate the Amount of Reactant Needed Stoichiometric Coefficient - The coefficients in chemical equations can be thought of as the number of moles of each substance involved in the reaction. Mole Ratio - Hypothetically, we can determine the amount of mole A needed to produce a certain amount of B, or the amount of B that can be formed given a certain among of A with the use of their mole ratio from the balanced chemical equation. 2A → 3B - 2 moles of A produces 3 moles of B, the mole relationship can be expressed as: To determine which mole ratio is useful to a certain calculation: Example 2: Nitromethane, a compound used a fuel, is burned according to the following rection:  General Chemistry 1 (First Quarter) Example 2: Aluminum oxide Al2O3 was prepared by the combustion of aluminum metal: Mole ratio – ratio of the coefficients of two substances in the balanced chemical equation. - Helps in converting the amount of reactant or product to the amount of the other substance involved in the reaction. Lesson 14: Calculate Percent Yield & Identify the Excess Reagent Stoichiometric Calculations - Plays important role in performing chemical experiments, especially in: Quantifying the amounts of reactants needed to prepare whenever one is to carry out a given reaction. Determining the expected amount of product given amount of reactants. Identifying the Limiting and Excess Reagents Yield – amount of the desired product obtained given a certain amount of reactants. Limiting Reagent (LR) – reactant which is allowed to be used up in a reaction. - Limits the maximum amount of products that can be Theoretical yield – the maximum expected amount of formed. product given a certain amount of reactant. - Gives smaller amount of P. Actual yield – actual amount of product gathered from Excess Reagent (ER) – reactant used in excess in a the experiment. reaction. - Usually lower than the theoretical yield due to number - Gives greater amount of P. of reasons (quality of reactants used, other unforeseen reactions, errors committed) Percent Yield – efficiency of a chemical reaction or the ratio of the actual yield to the theoretical yield expressed in percent. Example 1: Example 1: Aluminum oxide Al2O3 was prepared by the combustion of Calcium carbonate CaCO3 can be generated via aluminum metal: precipitation according to the equation: In a closed chamber, a 0.5024-mol sample of aluminum metal was combusted in the presence of 0.4573 mol of oxygen.  General Chemistry 1 (First Quarter) 1. Which of the two reactants is the limiting and excess reagent? 2. How many grams of urea can be generated in the reaction? 3. How many grams of the excess reagent remained 2. How many grams of aluminum oxide are unreacted? generated in the reaction? 3. How many grams of the excess reagent remain unreacted? Lesson 15: Pressure and its Common Units Pressure - ratio of force to the area on which the force is acted. - Force exerted by a body per unit area. - SI unit: Pascal (Pa) Atmospheric Pressure - Pressure exerted by gases in the atmosphere. Example 2: - Sea level = 1 atm. Urea, (NH2)2CO, a compound used as a fertilizer, is - industrially prepared from ammonia and carbon dioxide: For Gases - Pressure arises from the collision between gas molecules and the surface to which the molecule comes 1. Which of the two reactants is the limiting and the into contact. excess reagent? - The stronger the force involved in collision, the greater pressure the gas exerts. Barometer - Instrument used in measuring gas pressure. - First of this was invented by Evangelista Torricelli (Italian physicist).  General Chemistry 1 (First Quarter) o In his set-up, a glass tube sealed Aneroid Barometer on one end is filled with mercury. - Toxicity associated with mercury. o The tube is immersed in a - Has a metallic box that expands when the pressure is container filled with mercury. low and shrinks when the pressure is high. o A portion of mercury comes out - The movement of the box causes the movement of a of the tube until the pressure at the base of spring which makes the pointer of the dial move. the tube equals the pressure of air (blue - Pressure reading is taken from the dial. arrows). Lesson 16: Gas Laws to Determine Pressure, Volume, or Standard Atmospheric Pressure (atm) Temperature under Certain Conditions 1 atm = 760 mm Hg Millimeter of mercury (mm Hg) – torr (after Torricelli). Gas Laws – fundamental laws that shows how the Atmospheric pressure = 101 325 Pa. properties below are interrelated: Bar – unit that’s equal to 100 000 Pa n = amount in moles P = pressure / force exerted per unit Conversion Factors V = volume / space occupied by matter 1 atm = T = temperature / measure of hotness/coldness of an 101 325 Pa object. 101.325 kPa (kilopascal) 1.01325 bar BOYLE’S LAW 760 mm Hg - States that For a given amount of gas at 760 torr fixed temperature, the pressure exerted 29.92 in Hg (inches of mercury) by the gas is inversely proportional to its 14.696 psi or lb sub f/in^2 volume. - Constant: temperature Example 1: At the summit of Mt. Everest, the atmospheric - Robert Boyle studied the relationship between pressure pressure is about 33.7kPa. Convert the value to atmosphere, and volume of gas. bar, and millimeters of mercury. - He used a set-up, a J-shaped tube sealed on one end is filled with trapped gas and mercury. LEFT IMAGE: The gas has a pressure equal to the atmospheric pressure since the levels of mercury are equal. Consider the volume of gas inside is 8ml. RIGHT IMAGE: if the Example 2: A helium gas tank has an operating pressure of pressure is doubled by 27 psi. What is the value in atmosphere, pascals, and torr? adding mercury, the volume of the gas reduces by one- half of its original volume 4mL). Introducing a proportionality constant: Other Instruments for Measuring Gas Pressures Manometer - Used to measure the pressure of gases filled in a container. - U-shaped glass tube filled with mercury. - Has two types: Isotherm – plot showing the a) Closed-Tube Manometer relationship between V and P at - Used for samples whose pressures are below the a fixed temperature. atmospheric pressure. - Has a shape of hyperbola. - Sealed end has a vacuum (pressure at this side = 0). - Pressure of gas = the difference in heights of 2 mercury CHARLES’ LAW levels. - States that for a given amount of gas at fixed pressure, b) Open-Tube Manometer the volume of the gas is directly proportional to its - Has one arm open to the atmosphere; absolute temperature. - The pressure above the mercury at this side = the - Constant: pressure atmospheric pressure. - Separate studies from Jacques Charles and Joseph - Used for samples = or above the atmospheric pressure Gay-Lussac focused on the relationship between (> or = 1 atm). temperature and volume of given amount of gas at fixed pressure.  General Chemistry 1 (First Quarter) - They found out that the volume occupied by the gas increases as temperature increases, while the volume decreases as temperature decreases. (example: ball left outside overnight, it inflates then deflates). Isobar – plot shows relationship between temperature and volume at constant pressure. - Linear. - They project to a constant value of temperature at 0 volume. Absolute zero (zero-degree Kelvin) – equal to 0 on the kelvin scale, but equal to -273.15degreesCelsius on the Values of Molar Volume Celsius scale. - Considered to be the lowest possible temperature that can be attained. - Converting the temperature from the C-scale to the K- scale is given by: REMEMBER: Gas Laws – shows interrelation of the amount, pressure, volume, and temperature of gases. Boyle’s Law – illustrates the inverse proportionality of pressure and volume for a given amount of gas at constant temperature. Charles’ Law – illustrates the direct proportionality of volume and temperature of a given amount of gas at constant pressure; as well as the direct proportionality of pressure and temperature of a given amount of gas at constant volume. For a given amount of gas at a constant volume, the Avogadro’s Law – illustrates the direct proportionality pressure is directly proportional to its of volume and amount of gas at constant temperature absolute temperature. and pressure. Lesson 17: Ideal Gas Equation in Calculating PVT or # of Moles in Gas No gas allows all four gas laws under all condition. To study it and their behavior, they assumed that the gas is an idea gas and follows all four gas laws. P = pressure V = volume Isochore n = no. of moles - Temperature-pressure plot, linear. R = proportionality constant - Different isochores for gas differs on the slope but can T = temperature also be projected to zero pressure at T = 0. PV = nRT AVOGADRO’S LAW If R is: - Stated that at constant temperature and pressure, the kPa & L – 8.314.kPa/mol.K volume occupied by gas is directly proportional to its atm – o.0821L.atm/mol.K amount in moles). 1 atm = 1.01325 bar - Amedeo Avogadro hypothesized that equal volumes of different gases subjected at the same R = universal gas constant pressure and temperature have equal quantities of atoms or molecules. - The law enables to determine the molar volume of gases. Formulas: P = nRT/V Molar Volume – volume occupied by 1 mol of gas. T = PV/nR (proportionality constant k sub 4). n = PV/RT V = nRT/P  General Chemistry 1 (First Quarter) Example 1: - A form of the ideal equation that shows the relationships between pressure, temperature, and volume of a given amount of gas. - Combination of Boyle’s and Charles’ law. Example 2: Example 6: Example 3: Example 7: Example 4: Density of Gas Molar Mass: MM = m/n n = m/MM Example 5: Example 8: Combined Gas Law  General Chemistry 1 (First Quarter) Molar Mass of Gas Ideal gas equation is an equation for calculating the MM of an unknown gas given its conditions. Mole fraction – ratio of the amount in moles of a component to the total number of moles of all components. EXAMPLES Lesson 18: Dalton’s Law of Partial Pressure to Relate Mole Fraction and Partial Pressure of Gases in a Mixture Dalton’s Law of Partial Pressures - States that the pressure of a gaseous mixture equals the sum of the pressures of each component as if it were alone. - The ratio of partial pressure of a component to the total pressure is equal to its mole fraction in the mixture. Partial Pressure – pressure exerted by a component gas. Total Pressure – sum of these partial pressures. By the ideal gas equation, the partial pressures can be determined. Temperature & Volume is constant for all components Since they are all in one container at the same temperature.  General Chemistry 1 (First Quarter) Dalton’s Law of Partial Pressures - States that the pressure of a gaseous mixture equals the sum of the pressures of each component as if it were alone. - The ratio of partial pressure of a component to the total pressure is equal to its mole fraction in the mixture. Lesson 19: Gas Stoichiometry Dealing with Gas Stoichiometry Problems Steps in Calculating the Partial Pressure of a Component Given: moles of all components and total pressure: Example: Molar Volume – ratio of the volume to the number of moles. Recall: Some values of molar volume--- Sample Problems Example 2:  General Chemistry 1 (First Quarter) Example 3: Lesson 20: Graham’s Law of Effusion Diffusion – process in which gas particles is scattered in the entire container. Perfume sprayed in room. Respiration Effusion – process in which gas particles move into an evacuated vessel ( vessel without any gas inside ) through a pinhole or porous material. Example 4: Rate of Effusion: - Can be related to the root-mean-square speed of the gas particles. RMS of a gas with molar mass M at a certain T: Thomas Graham - Scottish chemist - Observed that the rate of effusion is inversely proportional to the mass of the particle—lighter gas particles tend to effuse faster than heavier ones. - This can be supported by comparing the rate of effusion of 2 gases w/ different molar mass:  General Chemistry 1 (First Quarter) RMS SPEED Example 1: Time of Effusion – directly proportional to the square root of the molar mass. Example 3: Example 2: DIFFUSION & EFFUSION – two phenomena illustrating random motion of gas particles. Graham’s Law – shows the inverse proportionality of the rate of effusion or diffusion of a gas to the square root of its molar mass.