Answer to Question #208419 in General Chemistry for Freya

Question

A sample of nitrogen gas is bubbled through water at 298K and the volume collected is 250.00 mL. The total pressure of the gas, which is saturated with water vapour is found to be at 98.8 kPa at 298 K. What amount in mole of nitrogen is in the sample? The vapour pressure of water at 298K is 3.17 kPa. (R = 0.08206 L.atm/mol.K)

Note: if your answer is in exponential form just like this: 5.99 x 10^-2 , express your answer in this form: 5.99E-2

Answer 1

P_water + $P_{N_2}$ = P_total

3.17 + $P_{N_2}$ = 98.8

$P_{N_2}$ = 95.63 kPa

T = 298K

V = 250 mL = 0.250 L

R = 0.0821

PV = n RT

95.63 × 0.250 = n × 0.0821 × 298

n = 0.977 mol

n = 9.77 E-1 mol