Answer:
The concentration of N2 at the equilibrium is 0.175 M (it's not between the options)
Explanation:
Step 1: Data given
Mixture contains 0.250 M N2 and 0.500 M H2
At the equilibrium [NH3] = 0.150 M
Step 2: The balanced equation
N2(g) + 3 H2(g) → 2 NH3(g)
Step 3: The initial concentrations:
[N2] = 0.250M
[H2] = 0.500 M
[NH3] = 0 M
Since [NH3] gained 0.15 M in going to equilibrium, then H2 lost (0.150)*(3/2) = 0.225
[H2] at the equilibrium = 0.500 -0.225 = 0.275 M
N2 lost (0.150/2)M = 0.075 M
[N2]at the equilibrium = 0.250 - 0.075 = 0.175 M
The concentration of N2 at the equilibrium is 0.175 M (it's not between the options)