Download Unit 3 Properties of Gases AP Chemistry Problem Set

Unit 3
Properties of Gases
AP Chemistry Problem Set
Screencast 3-5 Problems
30. Lowering the temperature of a system causes deviations from the ideal gas law. Explain.
Lowering the temperature causes a decrease in the molecular motion which causes the
space that is between the molecules to become smaller, make the assumption that the
space between the molecules no longer negligible. The molecules will then be attracted to
each other and the volume of the molecules themselves cannot be neglected in the
equation
31. A real gas will behave more like an ideal gas when the pressure of a system decreases
and the temperature remains the same. Explain.
This is because as the pressure decreases the volume of a gas increases at constant
temperature making the space between the molecules larger, thus there is no force of
attraction between the molecules
32. The following questions pertain to a system contains 122 g CO(g) in a 0.400 L container at
-7.1oC.
a. Calculate the pressure exerted by the CO(g) in this system using the ideal gas
equation.
b. The actual pressure exerted by the carbon monoxide was found to be 145 atm.
Explain why the actual pressure is less than what would be expected
Unit 3
Properties of Gases
AP Chemistry Problem Set
33. The normal boiling points of CO and SO2 are -192oC and -10oC, respectively.
a. At 25oC and 1 atm, which gas would you expect to have a molar volume closest to the
ideal value?
CO – it has a lower boiling point make the difference between the boiling point and
25o more significant and because it is a much smaller molecule (smaller molar mass)
b. If you wanted to reduce the deviation from ideal gas behavior in what direction would
you change the temperature? The pressure?
34. A sample of methane gas (CH4) is at 50oC and 20 atm. Would you expect it to behave
more or less ideally if
a. The pressure was reduced to 1 atm?
b. The temperature was reduced to -50 oC?