16. A sample of nitrogen gas,

N2, is collected in a 100 ml

container at a pressure of 688

mm Hg and a temperature of

565 °C. How many grams of

nitrogen gas are present in this

sample?

find mol of N2 present using gas law equation

PV = nRT

P = pressure = 688/760 = 0.905 atm.

V = 100mL = 0.1L

n = ?

R = 0.082057

T = 565+273 = 838

Substitute:

0.905*0.1 = n*0.082057*838

n = 0.0905 / 68.76

n = 0.00132 mol N2

Molar mass N2 = 28 g/mol

0.00132 mol = 0.00132*28 = 0.037g N2 gas