1. Calculate the number of moles and the number of molecules present in 0.25 L gas at 30 oC and p = 740 mm Hg. (use the SI units in your calculations).

2. A Dumas experiment to determine molar mass is conducted in which a gas samples P, T, and V are determined. If a 1.08-g sample is held in 0.250 dm3 at 303 K and 101.3 kPa: (a) What would the samples volume be at 273.15 K, at constant pressure? (b) What is the molar mass of the sample?

3. To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert blanketing gases. A chemical engineer puts a mixture of noble gases consisting of 5.50 g of He, 15.0 g of Ne, and 35.0 g of Kr in a piston-cylinder assembly at STP. Calculate the partial pressure of each gas.

4. Calculate the pressure exerted by 1.0 mol H2S behaving as a van der Waals gas when it is confined under the following conditions: (i) at 273.15 K in 22.414 dm3, (ii) at 500 K in 150 cm3.

5. Compare the values obtained for the pressure of 3.00 mol CO2 at 298.15 K held in a 8.25-dm3 bulb using the ideal gas and van der Waals equations.

6. A particular mass of N2 occupies a volume of 1.00 L at 50 C and 800 bar. Determine the volume occupied by the same mass of N2 at 100 C and 200 bar using the compressibility factor for N2. At 50 C and 800 bar it is 1.95; at 100 C and 200 bar it is 1.10. Compare this value to that obtained from the ideal gas law.