Question

Nitrogen gas reacts with hydrogen gas to form ammonia gas . You have nitrogen and hydrogen gases in a -L container fitted with a movable piston (the piston allows the container volume to change so as to keep the pressure constant inside the container). Initially the partial pressure of each reactant gas is atm. Assume the temperature is constant and that the reaction goes to completion. Calculate the partial pressure of ammonia in the container after the reaction has reached completion. Calculate the volume of the container after the reaction has reached completion.

Answer 1

ans)

from above data that

Hi....you can not given any values in the question,how can we find out the solutions

you can not give initial volume and initial pressures

i can assume that some values so you can give your values and check it

initial volume = 18 L

initial partial pressures  [N2] = [H2] = 1.0 atm

Now we can write the equation

N2 + 3H2 --> 2NH3     Kp = 0.018 [from literature]

Kp = [NH3]^2/[N2][H2]^3

initial pressures [N2] = [H2] = 1.0 atm

let x be the change at equilibrium,

0.018 = (2x)^2/(1-x)(1-3x)^3

0.018 - 0.162x + 0.486x^2 - 0.486x^3 = 4x^2

x = 0.05 atm

so at equilibrium partial pressures of,

we get

p[N2] = 1 - 0.05 = 0.95 atm

p[H2] = 1 - 3 x 0.05 = 0.85 atm

p[NH3] = 2 x 0.05 = 0.10 atm

total final pressure = 0.95 + 0.85 + 0.10 = 1.9 atm

total initial Pressure = 2.0 atm

initial volume = 18 L

final volume = 2 x 18/1.9

final volume = 18.95 L