Chapter Menu Gases Section 13.1Section 13.1The Gas Laws Section 13.2Section 13.2 The Ideal Gas Law Section 13.3Section 13.3 Gas Stoichiometry Exit Click a hyperlink or folder tab to view the corresponding slides.

Section 13-1 Section 13.1 The Gas Laws State the relationships among pressure, temperature, and volume of a constant amount of gas. scientific law: describes a relationship in nature that is supported by many experiments Apply the gas laws to problems involving the pressure, temperature, and volume of a constant amount of gas.

Section 13-1 Section 13.1 The Gas Laws (cont.) Boyle’s law absolute zero Charles’s law Gay-Lussac’s law combined gas law For a fixed amount of gas, a change in one variable—pressure, temperature, or volume—affects the other two.

Section 13-1 Boyle's Law Boyle’s law states that the volume of a fixed amount of gas held at a constant temperature varies inversely with the pressure.Boyle’s law P 1 V 1 = P 2 V 2 where P = pressure and V = volume

Section 13-1 Charles's Law As temperature increases, so does the volume of gas when the amount of gas and pressure do not change. Kinetic-molecular theory explains this property.

Section 13-1 Charles's Law (cont.)

Section 13-1 Charles's Law (cont.) Absolute zero is zero on the Kelvin scale.Absolute zero Charles’s law states that the volume of a given amount of gas is directly proportional to its kelvin temperature at constant pressure.Charles’s law

Section 13-1 Gay-Lussac's Law Gay-Lussac’s law states that the pressure of a fixed amount of gas varies directly with the kelvin temperature when the volume remains constant.Gay-Lussac’s law

Section 13-1 Gay-Lussac's Law (cont.)

Section 13-1 The Combined Gas Law The combined gas law states the relationship among pressure, temperature, and volume of a fixed amount of gas.combined gas law

Section 13-1 The Combined Gas Law (cont.)

Section 13-2 Section 13.2 The Ideal Gas Law Relate number of particles and volume using Avogadro’s principle. mole: an SI base unit used to measure the amount of a substance; the amount of a pure substance that contains 6.02 × representative particles Relate the amount of gas present to its pressure, temperature, and volume using the ideal gas law. Compare the properties of real and ideal gases.

Section 13-2 Section 13.2 The Ideal Gas Law (cont.) Avogadro’s principle molar volume ideal gas constant (R) ideal gas law The ideal gas law relates the number of particles to pressure, temperature, and volume.

Section 13-2 Avogadro's Principle Avogadro’s principle states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles.Avogadro’s principle

Section 13-2 Avogadro's Principle (cont.) The molar volume of a gas is the volume 1 mol occupies at 0.00°C and 1.00 atm of pressure.molar volume 0.00°C and 1.00 atm are called standard temperature and pressure (STP). At STP, 1 mol of gas occupies 22.4 L.

Section 13-2 The Ideal Gas Law Ideal gas particles occupy a negligible volume and are far enough apart to exert minimal attractive or repulsive forces on each other. Combined gas law to ideal gas law

Section 13-2 The Ideal Gas Law (cont.) The ideal gas constant is represented by R and is Latm/molK when pressure is in atmospheres.ideal gas constant The ideal gas law describes the physical behavior of an ideal gas in terms of pressure, volume, temperature, and amount.ideal gas law

Section 13-2 The Ideal Gas Law (cont.)

Section 13-2 The Ideal Gas Law—Molar Mass and Density Molar mass and the ideal gas law

Section 13-2 The Ideal Gas Law—Molar Mass and Density (cont.) Density and the ideal gas law

Section 13-2 Real Versus Ideal Gases Ideal gases follow the assumptions of the kinetic-molecular theory. Ideal gases experience: –There are no intermolecular attractive or repulsive forces between particles or with their containers. –The particles are in constant random motion. –Collisions are perfectly elastic. –No gas is truly ideal, but most behave as ideal gases at a wide range of temperatures and pressures.

Section 13-2 Real Versus Ideal Gases (cont.) Real gases deviate most from ideal gases at high pressures and low temperatures. Polar molecules have larger attractive forces between particles. Polar gases do not behave as ideal gases. Large nonpolar gas particles occupy more space and deviate more from ideal gases.

Section 13-3 Section 13.3 Gas Stoichiometry Determine volume ratios for gaseous reactants and products by using coefficients from chemical equations. coefficient: the number written in front of a reactant or product in a chemical equation, which tells the smallest number of particles of the substance involved in the reaction Apply gas laws to calculate amounts of gaseous reactants and products in a chemical reaction. When gases react, the coefficients in the balanced chemical equation represent both molar amounts and relative volumes.

Section 13-3 Stoichiometry of Reactions Involving Gases The gas laws can be applied to calculate the stoichiometry of reactions in which gases are reactants or products. 2H 2 (g) + O 2 (g) → 2H 2 O(g) 2 mol H 2 reacts with 1 mol O 2 to produce 2 mol water vapor.

Section 13-3 Stoichiometry and Volume-Volume Problems Coefficients in a balanced equation represent volume ratios for gases.

Section 13-3 Stoichiometry and Volume-Mass Problems Mass must be found by converting to moles or volumes. Plastics are some of the products created with polymers. One component of polymers is ethene gas, or ethylene.

Study Guide 1 Section 13.1 The Gas Laws Key Concepts Boyle’s law states that the volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature. P 1 V 1 = P 2 V 2 Charles’s law states that the volume of a fixed amount of gas is directly proportional to its kelvin temperature at constant pressure.

Study Guide 1 Section 13.1 The Gas Laws (cont.) Key Concepts Gay-Lussac’s law states that the pressure of a fixed amount of gas is directly proportional to its kelvin temperature at constant volume. The combined gas law relates pressure, temperature, and volume in a single statement.

Study Guide 2 Section 13.2 The Ideal Gas Law Key Concepts Avogadro’s principle states that equal volumes of gases at the same pressure and temperature contain equal numbers of particles. The ideal gas law relates the amount of a gas present to its pressure, temperature, and volume. PV = nRT

Study Guide 2 Section 13.2 The Ideal Gas Law (cont.) Key Concepts The ideal gas law can be used to find molar mass if the mass of the gas is known, or the density of the gas if its molar mass is known. At very high pressures and very low temperatures, real gases behave differently than ideal gases.

Study Guide 3 Section 13.3 Gas Stoichiometry Key Concepts The coefficients in a balanced chemical equation specify volume ratios for gaseous reactants and products. The gas laws can be used along with balanced chemical equations to calculate the amount of a gaseous reactant or product in a reaction.