[intex]

Hello everyone!

I am having a little trouble fully understanding the semantics of this question. For this answer I believe the answer is (B) - as oxygen gas exists as O₂ not O. However does the (298K) on the Δ_fH^o(298 K) relate to both the reactants and products as referred to in answer D?

Which statement is INCORRECT concerning the Δ_fH^o(298 K)for MgO(s).
(A)Δ_fH^o(298 K)refers to a reaction which produces 1 mol of MgO(s).

(B)Δ_fH^o(298 K)refers to a reaction which uses O(g) and Mg(s) as reactants.

(C)Δ_fH^o(298 K)refers to a reaction in which both reactants and products are at standard
pressure.

(D)Δ_fH^o(298 K)refers to a reaction in which both reactants and products are at298 K
Thanks!

[mjc123]

Yes, you are right, B is incorrect for the reason you give. And D is correct, both reactants and products are at 298K.