Chapter 5 Test Flashcards
A 2.32 L balloon contains helium at 1.00 atm and 25°C. How many grams of helium are contained in the balloon?
0.380 g He
If the molecules of a gas are strongly attracted to each other, the pressure will tend to be larger than the pressure predicted by the ideal gas law
false
Consider 20.0 moles of CO2 in a 1.00 liter container at 300.0 K. What is the pressure predicted by the van der Waals equation? The ideal gas law constant is 0.08206 [L•atm] / [mol•K]. For CO2, the pressure correction constant is 3.658 L2•atm / mol 2, and the volume correction constant is 0.04286 L / mol. Keep track of significant figures during individual calculations.
1980 atm
Calculate the average speed (rms speed) of a gas that has a molar mass of 2.08 × 10−2 kg / mol at a temperature of 22°C. The value for the gas constant, R, is 8.314 J / mol K.
595 m / s
Which of the following pairs of gases would be expected to effuse at about the same rate?
CO and N2
How high would a column of mercury rise in a mercury barometer if the atmospheric pressure is at 0.25 atm?
190 mm Hg
A helium balloon is filled to a volume of 2.5 L at atmospheric pressure. If the balloon is placed inside a sealed container and the pressure is reduced to 455 torr, what is the new volume of the balloon?
4.2 L
A sample of gas is heated. During the heating process, the volume of the gas increases 1.7 times. If the initial temperature of the gas is 80°C, what is the final temperature of the gas?
600 K
A helium balloon at a high altitude has 2.1 × 10^4 L of helium at 0.40 atm and −13°C. If the balloon descends to an altitude in which the atmospheric pressure is 1.00 atm and the temperature is 20°C, what will the volume of the balloon be at the lower altitude?
9.5 × 10^3 L
Two gas tanks are linked by a connecting tube of negligible volume with a valve. One contains 15 L of nitrogen at 7.2 atm of pressure. The other contains 8.3 L of helium at 4.1 atm of pressure. If the valve is opened, what is the final pressure of the two tanks combined?
6.1 atm
The larger the volume of the individual molecules of a gas, the more that gas behaves like an ideal gas.
false
A sample of helium gas, initially at standard temperature and pressure, is compressed to a smaller volume at constant temperature. What happens to the average speed of the gas molecules?
It remains constant.
A balloon containing 4.28 L of an unknown gas at 1.00 atm and 298 K has a mass of 16.90 g. The empty balloon has a mass of 2.24 g. What is the molar mass of the gas in the balloon?
83.8 g/mol
By the kinetic-molecular theory of gases, which of the following is affected by the number of gas molecules present?
frequency of collisions
According to the ideal gas law, PV = nRT, if the pressure of a gaseous compound in a 2.00 L container is 3.00 atm and the temperature is 20.0°C, how many moles of this compound are present?
0.250 mol
