1. When J.F. Piccard made a stratosphere flight in a helium filled balloon, the balloon seemed to be only half full as it left the ground near Detroit. The gas temperature was 27°c and the pressure was measured at 700mm Hg. The volume of the gas in the balloon was 80,000 cubic feet . What was the gas volume at a high altitude where the temperature is -3.0°c and the pressure is 400mm Hg?
2 1.50 liters of C4H10 is burned in excess oxygen. How many liters of CO2 will be produced at 25.0°c and 1.05 atm.?
3. A sample of air is analyzed and found to be 78.0% nitrogen and 22.0% oxygen. Determine the density of the air at 23°c and 0.95 atm.
4. The density of dry air at 40°c and 720 mm Hg is 1.15 g/l . Calculate the molecular weight of the gas.
5. A cylinder contains 45.0 grams of He, 56.0 grams of N2 and 42.0 grams of Ar. If the total pressure of the mixture is 10.0 atm., what is the partial pressure of the helium gas?
6. A mixture of Cu and Zn was analyzed for % Zn by adding an excess of HCl and collecting the H2 by water displacement. (Cu in the sample does not react with the HCl) The H2 collected has a volume of 25.0ml at a pressure of 0.91atm and a temperature of 29°c. If the original sample weighed 1.50 grams, what is the percent of Zn in the sample? (VP =30.2torr)
7. Calculate the ratio of the rate of diffusion of UF6 which are made form U235 and U238 isotopes.
8. A cylinder contains 75.0 g of CO2 and 25.0 g of O2 If the total pressure of the mixture is 1.5 Atm. what is the partial pressure of the CO2?
9. A compound contains only C, H, and N. It is 58.51% C and 7.37% H by mass. If 6.03g of this gas occupies 1.50L of space at 25°C and 1.2Atm. ; Calculate the empirical formula, Molecular mass and molecular formula for this gas
10. Real gases approach ideal behavior at:
(a) high temperature and low pressure (b) low temperature and low pressure
(c) low temperature and high pressure (d) high temperature and high pressure
Answers:
1.) 12,600cubic feet
2) 6.0L
3) 1.12g/L
4) 31.2 g/mole
5) 7.87 atm
6) 3.82%
7) 1.004:1
8) 1.03 atm
9) C2H3N, 82g/mol, C4H6N2
10) A