In the reaction below, ΔH°f is zero for ___________.

Question

Ni(s) + 2CO(g) + 2PF3(g) = Ni(CO)2(PF3)2(l)

Ni(s)

CO(g)

Ni(CO)2(PF3)2(l)

both CO(g) and PF3(g)

PF3(g)

Answer 1

The standard heat of formation for any element in its natural state is zero.

Therefore, ΔH°f for Ni(s) is zero.