Chem 110, 2002 upper right
Useful information: PV = nRT R = 0.08206 L.atm.K-1mol-1 1 atm = 760 Torr (or mmHg) K = °C + 273.15
1. A balloon is filled with helium. Its volume is 4.83 L at 24 °C. What will be its volume at –195 °C if the pressure remains constant?
This problem exemplifies the gas law named after _____________________.
2. In the chemical reaction used in the automotive air bag safety systems, N2(g) is produced by the decomposition of sodium azide, NaN3:
2 NaN3(s) ® 2 Na + 3 N2(g)
a. If you decomposed 50.0 g of NaN3 (F.W.=65.01), how many moles of N2(g) would be formed?
b. Based on your answer to 2a, what volume (in L) would this N2(g) occupy at a pressure of 767 Torr
and a temperature of 24°C?
3. Calculate the molar mass of a gas if 0.440 g occupies 179 mL at 86°C and 741 Torr.
4. Hydrogen is collected over water at 18 °C. The total pressure in the collection flask is adjusted to the barometric pressure of 738 Torr. At 18°C, water vapor pressure is 15.5 mmHg. Calculate the partial pressure of the hydrogen.