Question

The enthalpy of formation of $H^{+}\left(g\right)$ is 1536 kJ/mole. What is the heat of formation of $H_2$, gas?

• A. 3072 kJ
• B. 1536 kJ
• C. 0
• D. -1536 kJ
• E. -3072 kJ

Answer 1

The correct option is C 0

The standard enthalpy of formation for hydrogen gas, or for any free element in its standard state for that matter, is by definition zero.

As per convention, the specific heat of formation of all elements in their naturally existing state is considered as 0 kJ/kg at STP conditions. Since hydrogen exists as a diatomic molecule $H_2$ in its natural state, Specific Heat of formation of $H_2$ is 0 kJ/kg