More Unit 10 Practice Problems!

1.) A 20.83 g sample of a gas occupies 4.167 L at 79.97 kPa at 30.0 °C. What is its molecular mass?

2.) Determine the number of moles of Kr contained in a 3.25 liter gas tank at 5.80 atm and 25.5 °C.
If the gas is oxygen
instead of krypton, will the answer be the same? Why or why not?

3.) Determine the number of grams of CO2 in a 450.6 mL tank at 1.80 atm and -50.5 °C.  Determine
the number of grams of oxygen that the same container will contain under the same
temperature and pressure.

4.) A sample of gas is put into a container that has a movable piston. Initially the volume is 4.00 liters when
the pressure is 600. mm Hg and the temperature is 50.0oC. What will be the new volume if the pressure
and temperature are both tripled?

5.) A mixture of 3 gases (composed of Ne, He, and O2) exerts a total pressure of 990. torr.  If there are 10.0
moles each of He & Ne, and there is 4.00 moles of O2, what is the partial pressure exerted by the O2 gas?

6.) What is the density of bromine vapor (in grams/liter) at 775oC and 75.5 kPa?