The Haber reaction for the manufacture of ammonia is: N2 + 3H2 → 2NH3 Without doing any experiments, which of the following can you say MUST be true?

Question

1. The activation energy is positive.
2. Disappearance rate of N2 = 3 (Disappearance rate of H2).
3. The reaction is first order in N2.
4. Disappearance rate of H2 = 3 (Disappearance rate of N2).
5. The reaction is not an elementary reaction.
6. Δ[H2]/Δt will have a positive value.
7. Reaction rate = -Δ[N2]/Δt.

Answer 1

The stoichiometry of the reaction gives a 3:1 rate of reaction between H₂ and N₂. So, 4.