The standard enthalpy change for the following reaction is 186 kJ at 298 K. CaH2(s) Ca(s) + H2(g) What is the standard heat of formation of CaH2(s)? kJ/mol

Question

The standard enthalpy change for the following reaction is 186 kJ at 298 K.

1. CaH₂(s) Ca(s) + H₂(g)

What is the standard heat of formation of CaH₂(s)?  kJ/mol

Answer 1

CaH₂(s) <==> Ca(s) + H₂(g) ∆H = 186 kJ

Ca(s) + H₂(g) <==> CaH₂(s) ∆H = -186 kJ