GT CHEMISTRY

UNIT: Gases

Name: ______Date: ______MOD: ______

Day 1: ______

Boyles’s Law Lab: Read the Boyles’s Law Lab and complete the pre-lab below. Write any questions you may have about the lab on the lab paper.

  1. State Boyle’s Law in your own words. Then write the mathematical equation for Boyle’s Law.
  1. When the piston in the Boyle’s Law apparatus is at rest, what is the relationship between the pressure and the trapped gas, and the pressure on the outside of the piston?
  1. What are the possible sources of external pressure on the piston during this investigation?
  1. What is the benefit of collecting eight (8) sets of data during this investigation?
  1. In what ways can you minimize the risk of personal injury or damage to the equipment?

Day 2: ______

Boyle’s Law Problems: Use Boyle’s law to solve the following problems for the missing variable.

1. If 0.756 L of gas exerts a pressure of 94.6 kPa, what would the volume be at standard pressure (101.325 kPa)?

2. If 468 mL of gas is measured at 0.83 atm, then what volume would the gas occupy at 1.05 atm?

5. A gas is initially under a pressure of 1140 mmHg. If the pressure is reduced to 0.94 atm and the new volume is measured to be 80 mL, what was the original volume of the gas?

Day 3: ______

The Gas Laws

Boyles’s Law:

  1. A balloon contains 30.0 L of helium gas at 103 kPa. What is the volume of the helium when that balloon rises to an altitude where the pressure is only 25.0 kPa? (Assume that the temperature remains constant)

Charles’s Law: (Don’t forget to change the temperature to Kelvin)

  1. A balloon inflated in a room at 24º C has a volume of 4.00 L. The balloon is then heated to a heated to a temperature of 58º C. What is the new volume if the pressure remains constant?

Gay-Lussac’s Law: (Don’t forget to change the temperature to Kelvin)

  1. Aerosol cans carry warnings on their labels that say not to incinerate (burn) them or store the cans above a certain temperature. This problem will show shy it is dangerous to dispose of aerosol cans in a fire. The gas in a used aerosol can is at a pressure of 103 kPa at 25º C. If the can is thrown onto a fire, what will the pressure be when the temperature reaches 928º C.

Combined Gas Law: (Don’t forget to change the temperature to Kelvin)

  1. The volume of a gas-filled balloon is 30.0 L at 313 K and 153 kPa pressure. What would the volume be at standard temperature and pressure (STP)?

Day 4: ______

Gas Laws the Effect of Temperature on Volume:Read Lab

Ideal Gas Law:Answer the following question:

Some racing enthusiasts fill their automobile tires with pure nitrogen instead of air. Assume that the tire pressure is 2.40 kPa and that the average molar mass of air is 28.8 g/mole. Assume a typical tire holds 19.6 L of gas and have an internal temperature of 49.0 °C. What would be the advantage of using pure nitrogen? Support your answer with mathematical calculations.

Day 5: ______

Gas Laws the Effect of Temperature on Volume:Complete analysis questions

Graham’s Law of Diffusion: Read the lab and complete the Pre-lab below.

  1. What is the formula relating kinetic energy to particle velocity? Identify the variables.
  1. Distinguish between effusion and diffusion. Which are we studying in this lab?
  1. How does the average kinetic energy of different gases compare when they are at the same temperature?
  1. What are the molar masses of HCl and NH3?
  1. Write an equation for the formation of ammonium chloride from ammonia and hydrogen chloride.

6. A container filled with methane, CH4, and an unknown gas. If the rate of diffusion of

the methane is 2.00 times the rate of the unknown gas, what is the molar mass of the

unknown gas?

Day 6: ______

Graham’s Law of Diffusion

Graham’s Law of diffusion: The relative rates of diffusion of two gases under identical conditions vary inversely as the square roots of their molar masses.

V1 = velocity of gas given

V2 = velocity of unknown gas

m1 = molar mass of first gas

Formula:m2 = molar mass of second gas

Solve the following:

  1. Two balloons of the same size and like material are filled respectively with hydrogen gas, H2 and oxygen gas O2 at the same temperature and pressure. If the oxygen escapes at the rate of 65 ml/hr, calculate the rate of escape of hydrogen.
  1. If methane gas, CH4, diffuse at a rate of 20 ml/sec, how fast will sulfur dioxide diffuse?
  1. Two porous containers were filled respectively with hydrogen and oxygen. At the end of one hour, 888 ml of hydrogen had escaped. How much oxygen had escaped during the same time?
  1. It takes 36 seconds for He to effuse through a pinhole in an effusion apparatus. It takes 72 seconds for another gas to effuse through the same system. What is the molar mass of the other gas?
  1. How many times faster does helium gas diffuse that SO2?
  1. How many times faster does fluorine gas diffuse than carbon dioxide?
  1. How many times faster does hydrogen diffuse than oxygen?
  1. A porous container was filled with equal amounts of oxygen and a gas of unknown molar mass. The oxygen escaped 1.77 times faster than the unknown gas. Calculate the molar mass of the unknown gas.
  1. A container is filled with methane and an unknown gas of unknown molar mass. If the rate of diffusion of the methane is 2.00 times the rate of the unknown gas, what is the molar mass of the unknown gas?
  1. An unknown gas, X, has a rate of diffusion measured to be 1.14 times that of carbon dioxide. What is the molar mass of gas X?

Gas Laws:Study for Gas Laws Exam by completing benchmark review packet.

Day 7: ______

Extra Credit: Complete Gas Laws Extra Credit on edline due by: ______