Lycoming College                                          Quiz 6                                                  Write name on back

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 24C?










3.   Calculate the molar mass of a gas if 0.440 g occupies 179 mL at 86C 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 18C, water vapor pressure is 15.5 mmHg.  Calculate the partial pressure of the hydrogen.