What is the enthalpy of the reaction? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants.. –1,839.6 kJ –1,179.8 kJ 1,179.8 kJ 1,839.6 kJ
2 C (s, graphite) + H2 (g) -> C2H2 (g)
The enthalpy of formation (ΔHf) of C2H2 (g) is 226.73 kJ/mol.
The enthalpy of formation of C (s, graphite) is zero because Carbon is in its elemental state.
The enthalpy of formation of H2 (g) is zero because is taken as a reference.
ΔHrx = ∑ΔHf of products - ∑ΔHf of reactants = 226.73 kJ/mol * 1 mol - 0 = 226.73 kJ
Note: 1 mol of C2H2 is formed.
A) –1,839.6 kJ