CHM 1045
Dr. Michael Blaber

Name_________________________

SS #__________________________

Exam #4 100 points total

  1. Name three characteristics of gasses which distinguishes them from solids or liquids (6 points)

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  2. At the top of Mount Everest a 1m2 column of air has a mass of 7,300 kg. What is the atmospheric pressure on the top of Mount Everest? (5 points)

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  3. What is the pressure, in atmospheres, of the gas in the following open-tube manometer? Assume that atmospheric pressure is 102 kPa. (5 points)

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  4. A 7.31 liter sample of gas at 50° C and 2.82 atm of pressure is subsequently compressed to 0.546 liters. In response to being compressed, the temperature increases to 72° C. What is the pressure of the gas after this compression? (5 points)

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  5. A small balloon holds 0.823 L of gas at standard temperature and pressure. How many moles of gas are in the balloon? (5 points)

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  6. What is the volume of a 5.7 mol sample of gas at 0.0231 atm pressure at 3° C? (5 points)

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  7. What is the density of Carbon dioxide gas at 1.83 atm and 42°C? (5 points)

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  8. An artificial atmosphere for the planet Jupiter consists of 92% hydrogen and 8% helium. 15g of this gas mixture are placed in a 50L container at –25°C. What is the partial pressure of each gas? (5 points) What is the mole fraction of hydrogen and helium in the artificial atmosphere? (5 points)

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  9. A car runs on propane (C3H8) gas and has a tank with a volume of 210L. How many grams of propane will the tank hold if it can be pressurized to 3.25 x 103 kPa at 30°C? (5 points)

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  10. In question #9, if the car burn through an entire tank full of propane, how many grams of water are produced? (5 points)

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  11. A box contains 4 molecules of Carbon dioxide. Their individual velocities are 64.7, 23.8, 4.9 and 39.6 m/s. What is the average kinetic energy (in Joules) of these gaseous molecules? (5 points)

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  12. What is the rate of diffusion for a molecule of diatomic oxygen compared to a molecule of carbon dioxide? (5 points)

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  13. Van der Waals constants for water are a = 5.46 L2 atm/mol2 and b= 0.0305 L/mol. Calculate the pressure exerted by 2.8 g of water vapor at 125° C in a container with a volume of 5.3L (5 points)

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  14. What is the enthalpy change associated with the heating of 53g of H2O from 250K to 400K? (10 points)

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  15. Identify the changes in processes indicated in the following phase diagram (6 points)

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  16. The critical temperature of H2O is 647.6 K and the critical pressure is 217.7 atm. A).What state of H2O would you expect at 650K and 10,000 atm? B). What state would you expect at 645K and 220 atm? (5 points)

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  17. In the lattice diagram below, draw a border around a unit cell and indicate an asymmetric unit of the unit cell (5 points)

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  18. What type of attractive interactions would allow Noble gas atoms to condense into the liquid phase? (3 points)

 

 

 

 

Exam 4 Appendix

Acceleration due to Earth Gravity: 9.78 m/s2

Gas constant R: 0.0821 L atm/mol K

8.31 J/mol K

Mass: 1 amu = 1.66 x 10-24 g

Energy: 1 J = 1 kg m2/s2

Pressure: 1 Pa = 1 N/m2

1 atm = 101 kPa

1 atm = 760 torr

van der Waals gas equation:

Specific heat of ice: 2.09 J/g K

Specific heat of liquid water: 4.18 J/g K

Specific heat of water vapor: 1.84 J/g K

DHfus H2O: 6.01 kJ/mol

DHvap H2O: 40.67 kJ/mol