ΔHr = Σ ΔHf – Σ ΔHf.
ΔHr = Σ ΔHf – Σ ΔHf. Correct Answer – Σ ΔHf. ] true
The equation ΔHr = Σ ΔHf – Σ ΔHf says that the enthalpy of a reaction is the difference between the enthalpy of products and enthalpy of reactants. The above statement regarding enthalpy is true.