[LHM]

For the reversible reaction

N₂(g) + 3H₂(g)  2 NH₃(g)

the rate of the forward reaction is much larger than the rate of the reverse reaction when:

A) there is an excess of NH₃ and little N₂ and H₂
B) the reaction is at equilibrium
C) NH₃ is present but no H₂ and N₂ are present
D) N₂ and H₂ but no NH₃ are present

The answer is A but it hasn't always been so reliable so is this really the answer? If so, why? Why isn't the answer D since if there's only N₂ and H₂ then shouldn't the rate of the forward reaction be greater?

Also as a side question, since I started thinking about it just now, if the above reaction is at equilibrium and you add N₂ to the system, would the rate of the forward reaction increase? And would the rate of the reverse reaction decrease too along with the rate of the forward reaction increasing?

[rabolisk]

The answer is D for all the reasons you stated.

[opti384]

I agree with rabolisk. The answer is definitely D.

[AMEDIO]

ya i agree
the answer has to be D.