05 Gases General Chemistry 1 PDF

05 GASES GENERAL CHEMISTRY I LESSON OVERVIEW ▪ Behavior of Gases ▪ Gas Laws ▪ The Ideal Gas Law 5.1 BEHAVIOR OF GASES PROPERTIES OF GAS PARTICLES Gases consists of particles that are relatively far apart as compared to solids and liquids. Gas particles move about rapidly. Gas particles ha...

05 GASES GENERAL CHEMISTRY I LESSON OVERVIEW ▪ Behavior of Gases ▪ Gas Laws ▪ The Ideal Gas Law 5.1 BEHAVIOR OF GASES PROPERTIES OF GAS PARTICLES Gases consists of particles that are relatively far apart as compared to solids and liquids. Gas particles move about rapidly. Gas particles have little effect on one another unless they collide. Gases expand to fill their containers. BEHAVIOR OF GASES All gases expand if heated and contract if cooled. Changes in pressure and amount of gas affect the behavior of gas. Flat tire Blowing up a Balloon Exercise ball PRESSURE OF A GAS Force of gas particles colliding with the walls of a container 5.2 GAS LAWS BOYLE’S LAW Physicist Robert Boyle “The volume of a given amount of gas is inversely proportional to its pressure at constant temperature” BOYLE’S LAW BOYLE’S LAW If 22.5 L of nitrogen at 748 mm Hg are compressed to 765 mm Hg at constant temperature. What is the new volume? CHARLES’S LAW Scientist Jacques Charles “The volume of a given amount of gas is directly proportional to its absolute temperature at constant pressure” CHARLES’S LAW  CHARLES’S LAW A container containing 5.00L of gas is collected at 100 K and then allowed to expand to 20.0 L. What must be the new temperature in order to maintain the same pressure? 𝑉 1 𝑉 2 = 𝑇 1 𝑇 2 00 𝐿 20. 0 𝐿 𝑇 2 ∙ 5.00 𝐿= 100 𝐾 ∙ 20.0 𝐿 = 00 𝐾 𝑇2 𝑇 2 ∙ 5.00 𝐿= 2000.0 𝐾 ∙ 𝐿 GAY-LUSSAC’S LAW Chemist and Physicist Joseph Louis Gay-Lussac “At a fixed volume, the temperature and pressure of a gas are directly proportional to each other” GAY-LUSSAC’S LAW GAY-LUSSAC’S LAW The gases in a hair spray can are at a temperature of 27 degrees Celcius and a pressure of 30. If the gases in the can reach a pressure of the can will explode. To what temperature must the gases be raised for the can to explode? Assume the volume is constant. AVOGADRO’S LAW Lorenzo Romano Amadeo Carlo Avogadro “The volume of a gas at a given temperature is directly proportional to the number of moles contained in the volume” AVOGADRO’S LAW AVOGADRO’S LAW A flexible container at an initial volume of 5.12L contains 8.5 mol of gas. More gas is then added to the container until it reaches a final volume of 18.1L. Assuming the pressure and temperature of the gas remain constant, calculate the number of moles of gas added to the container. COMBINED GAS LAW The relationship shared by pressure, volume and temperature: the variables found in other gas laws, such as Boyle’s law, Charles’s Law and Gay-Lussac’s Law. COMBINED GAS LAW A gas is heated from 263 K to 298 K and the volume is increased from 24 liters to 35 liters by moving a large piston within a cylinder. If the original pressure was 1 atm, what would the final pressure be? 𝑃 2 ∙ ( 35 𝐿 ) ( 263 𝐾 ) =( 1 𝑎𝑡𝑚 ) ( 24 𝐿 ) ( 298 𝐾 ) ( 1 𝑎𝑡𝑚 ) ( 24 𝐿 ) ( 298 𝐾 ) 𝑃 2= ( 35 𝐿 ) ( 263 𝐾 ) 𝑷 𝟐 =𝟎. 𝟕𝟕𝟕𝟎 𝒂𝒕𝒎 5.3 THE IDEAL GAS LAW IDEAL GAS LAW The combination of all Simple Gas Laws: Boyle’s Law, Charles’ law and Avogadro’s Law. Where: P= pressure V= volume n=amount of gas particles T= temperature STANDARD TEMPERATURE AND PRESSURE 𝑃𝑉 =𝑛𝑅𝑇 (1 STANDARD TEMPERATURE AND PRESSURE STP commonly is used when standard state conditions are applied to calculations. ▪ Standard Temperature = 273 K ▪ Standard Pressure = 1 atm IDEAL GAS LAW A gas canister can tolerate internal pressure up to 210 atmospheres. If a 2L canister holding 3.5 moles of gas is heated to, will the canister explode? 𝑃 𝑃 (2 𝑃𝑉 =𝑛𝑅𝑇 𝑃= 5.4 DALTON’S LAW OF PARTIAL PRESSURE DALTON’S LAW OF PARTIAL PRESSURE “The total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases” DALTON’S LAW OF PARTIAL PRESSURE Blast furnaces gives off many unpleasant and unhealty gases. If the total air pressure is 0.99 atm, the partial pressure of carbon dioxide is 0.05 atm, and the partial pressure of hydrogen sulfide is 0.02 atm, what is the partial pressure of the remaining gas?