Question

In the reaction below delta H°f is zero for?

Ni (s) + 2 CO (g) --> Ni(CO)2(PF3)2 (l)
A. CO (g)
B. PF3 (g)
C. Ni(CO)2(PF3)2 (l)
D. Ni(s)
E. both CO (g) and PF3 (g)

Answer 1

The enthalpy change, ΔH°f, is zero for both A) CO (g) and B) PF3 (g) in the given reaction.

Step-by-step explanation:

The enthalpy change, ΔHof, is zero for both CO (g) and PF3 (g) in the given reaction: Ni (s) + 2 CO (g) → Ni(CO)2(PF3)2 (l).

This is because the standard enthalpy of formation, ΔHf, is defined as the enthalpy change when one mole of a compound is formed from its elements in their standard states, and the standard enthalpy of formation for elements in their standard states is zero.

Therefore, the correct answer is option E. both CO (g) and PF3 (g).