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Gases. Section 13.1 The Gas Laws Section 13.2 The Ideal Gas Law Section 13.3 Gas Stoichiometry. Click a hyperlink or folder tab to view the corresponding slides. Exit. Chapter Menu. Section 13.1 The Gas Laws.
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Gases Section 13.1The Gas Laws Section 13.2The Ideal Gas Law Section 13.3Gas Stoichiometry Click a hyperlink or folder tab to view the corresponding slides. Exit Chapter Menu
Section 13.1 The Gas Laws Statethe relationships among pressure, temperature, and volume of a constant amount of gas. Applythe gas laws to problems involving the pressure, temperature, and volume of a constant amount of gas. scientific law: describes a relationship in nature that is supported by many experiments 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. P1V1 = P2V2 where P = pressure and V = volume Section 13-1
Practice p 443 The volume of a gas at 99 kPa is 300 ml. If the pressure is increased to 188 kPa, what will be the new volume? The pressure of a sample of helium in a 1 L container is 0.988 atm. What is the new pressure if the sample is placed in a 2 L container? Air trapped in a cylinder fitted with a piston occupies 145.7 mL at 1.08 atm pressure. What is the new volume when the piston is depressed, increasing the pressure by 25%?
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 zerois zero on the Kelvin scale. Charles’s law states that the volume of a given amount of gas is directly proportional to its kelvin temperature at constant pressure. Section 13-1
Practice p 446 A balloon is 4.3 L at 350 K. What volume will the gas in the balloon occupy at 250K?
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. Section 13-1
Gay-Lussac's Law (cont.) Section 13-1
The Combined Gas Law The combined gas lawstates the relationship among pressure, temperature, and volume of a fixed amount of gas. Section 13-1
The Combined Gas Law (cont.) Section 13-1
A B C D Section 13.1 Assessment Boyle’s Law explains which relationship of properties in gases? A.pressure and volume B.amount and pressure C.temperature and volume D.volume and temperature Section 13-1
A B C D Section 13.1 Assessment Atoms are in their lowest energy state at what temperature? A.0° Celsius B.0° Fahrenheit C.–100° Celsius D.0 kelvin Section 13-1
Section 13.2 The Ideal Gas Law Relatenumber of particles and volume using Avogadro’s principle. Relatethe amount of gas present to its pressure, temperature, and volume using the ideal gas law. Comparethe properties of real and ideal gases. mole:an SI base unit used to measure the amount of a substance; the amount of a pure substance that contains 6.02 × 1023 representative particles 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 principlestates that equal volumes of gases at the same temperature and pressure contain equal numbers of particles. 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. 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 constantis represented by R and is 0.0821 L•atm/mol•K when pressure is in atmospheres. The ideal gas law describes the physical behavior of an ideal gas in terms of pressure, volume, temperature, and amount. 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 13-2
A B C D Section 13.2 Assessment Which of the following is NOT one of the related physical properties described in the ideal gas law? A.pressure B.volume C.density D.temperature Section 13-2
A B C D Section 13.2 Assessment 3.00 mol of O2 at STP occupies how much volume? A.30.0 L B.22.4 L C.25.4 L D.67.2 L Section 13-2
Section 13.3 Gas Stoichiometry Determinevolume ratios for gaseous reactants and products by using coefficients from chemical equations. Applygas laws to calculate amounts of gaseous reactants and products in a chemical reaction. 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 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. 2H2(g) + O2(g) → 2H2O(g) • 2 mol H2 reacts with 1 mol O2 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. Section 13-3
A B C D Section 13.3 Assessment How many mol of hydrogen gas are required to react with 1.50 mol oxygen gas in the following reaction? 2H2(g) + O2(g) → 2H2O(g) A.1.00 B.2.00 C.3.00 D.4.00 Section 13-3
A B C D Section 13.3 Assessment How many liters of hydrogen gas are required to react with 3.25 liters of oxygen gas in the following reaction? 2H2(g) + O2(g) → 2H2O(g) A.2.00 B.3.25 C.4.00 D.6.50 Section 13-3
Chemistry Online Study Guide Chapter Assessment Standardized Test Practice Image Bank Concepts in Motion Resources Menu
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. P1V1 = P2V2 • 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 1
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 2
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. Study Guide 3
A B C D What does the combined gas law relate? A.pressure and temperature B.volume and pressure C.pressure, temperature, and volume D.pressure, temperature, volume, and amount Chapter Assessment 1
A B C D According to Charles’s law, if pressure and amount of a gas are fixed, what will happen as volume is increased? A.Temperature will decrease. B.Temperature will increase. C.Mass will increase. D.Mass will decrease. Chapter Assessment 2
A B C D Equal volumes of gases at the same temperature and pressure contain equal numbers of particles is stated by: A.Law of conservation of mass B.Boyle’s law C.Avogadro’s principle D.Ideal gas law Chapter Assessment 3
A B C D What is the volume of 1.00 mol of chlorine gas at standard temperature and pressure? A.1.00 L B.18.0 L C.22.4 L D.44.8 L Chapter Assessment 4
A B C D When do real gases behave differently than ideal gases? A.high temperature or low pressure B.high temperature or high pressure C.low temperature or low pressure D.low temperature or high pressure Chapter Assessment 5
A B C D If two variables are directly proportional, what happens to the value of one as the other decreases? A.increases B.decreases C.remains constant D.none of the above STP 1