The enthalpy of reaction for the reaction :
2H₂(g) + O₂(g) → 2H₂O(l) is ∆H_r^Θ = – 572 kJ mol^–1

What will be standard enthalpy of formation of H₂O (l)?

Question

The enthalpy of reaction for the reaction : 2H 2 (g) + O 2 (g) → 2H 2 O( l ) is ∆H r Θ = – 572 kJ mol –1 What will be standard enthalpy of formation of H 2 O ( l) ?

Philoid · Accepted Answer

The standard enthalpy of formation of H₂O (l ) can be obtained by considering the following reaction :

As Δ_fH^Θ is related with one mole of a substance at standard conditions.

For the given reaction : 2H₂(g) + O₂(g) →2H₂O(l) the standard enthalpy of reaction is ∆H_r^Θ = – 572 kJ mol^–1 , so the half of ∆H_r^Θ will be the standard molar enthalpy of formation ;

Δ_fH^Θ = 1/2 × ∆H_r^{Θ =} (-572/2) = -286 kJ mol^–1 .

The enthalpy of reaction for the reaction :2H2(g) + O2(g) → 2H2O(l) is ∆HrΘ = – 572 kJ mol–1What will be standard enthalpy of formation of H2O (l)?

The enthalpy of reaction for the reaction :
2H₂(g) + O₂(g) → 2H₂O(l) is ∆H_r^Θ = – 572 kJ mol^–1

What will be standard enthalpy of formation of H₂O (l)?