Name:______Date:______Period:___

Gases Review – GT

Standard Temp = 273 K

Standard Pressure = 1 atm = 101.3 kPa = 760 mmHg

R = 8.31 L*kPa/mol*K OR 0.0821 L*atm/mol*K

**This information will be given! 

Directions: For problems 1-6, state the gas law needed to solve each problem. Then, apply the law, showing work, to solve the problem with correct number of sig figs.

  1. A 50.0 L tire has a pressure of 75.0 kPa at 45.1oC. What is this volume at STP?

Law: ______

Answer: ______

  1. The Earth’s atmosphere is approximately 78.1 % N2, 20.9% O2 and 1.00 % H2O. If the air pressure on a given day is 1.25 atm, calculate the partial pressure of each gas.

Law: ______

Answer: ______

  1. Calculate the pressure of 2.78 g of Ne in a 5.00 L flask at -10oC.

Law: ______

Answer: ______

  1. Calculate the new pressure on a container when a gas at 23.1 kPa and 0oC is suddenly heated to 50.0oC.

Law: ______

Answer: ______

  1. A 100.0 L tire has a pressure of 2.5 atm. What is the pressure if the volume is increased to 137.0 L?

Law: ______

Answer: ______

  1. A weather balloon typically has a volume of 500.0 L. What will the volume be if the temperature drops from 25.0oC to -40.0oC?

Law: ______

Answer: ______

  1. What is an ideal gas?
  1. What is the difference between effusion and diffusion?
  1. Why don’t gas molecules diffuse nearly as rapidly as their high speed suggest?
  1. Write a balanced chemical equation for the combustion of methane (CH4) to form carbon dioxide and water. Then if the methane has a volume of 0.65L when under 100. kPa of pressure and at a temperature of 305K, what mass of carbon dioxide would be produced during the reaction?
  1. What is the pressure in atmospheres of a gas mixture that contains 1.0 grams of hydrogen and 8.0 grams of argon in a 3.0L container at 27oC?
  1. There is a mixture of 16 moles fluorine, 7 moles chlorine, and 2 moles of bromine gases. What is the mole fraction of each gas?

b. If the total pressure of the mixture is 156 kPa, what is the partial pressure of each gas?

  1. 5.98 grams of a gas occupies 2045 mL at 25 degrees C and a pressure of 740 mmHg. What is the molecular mass of the gas?
  1. Hydrogen sulfide, H2S, has a very strong rotten egg odor. Methyl salicylate, C8H8O3, has a wintergreen odor, and benzaldehyde, C7H6O, has a pleasant almond odor. If the vapors for these three substances were released at the same time from across a room, which odor would you smell first? Show your work and explain your answer.
  1. How much faster does hydrogen escape through a porous container than sulfur dioxide?

  1. What happens at the triple point of a substance? The critical point?
  1. How can you turn a sample of carbon dioxide into a liquid at standard atmospheric pressure?
  1. If dry ice (solid carbon dioxide) is removed from a freezer at -92°C at standard pressure, what will happen to the substance as it comes to room temperature? What would you have to do to this substance in order to be able to drink it?
  1. At a pressure of 1000atm, what is the approximate melting point of CO2? Boiling point?

**Look at all practice we have done in class to see other examples… you should know how to do those as well!! 