Related Problems with Solutions

Problem 1 : Calculate the standard enthalpy change (∆H°) for the reaction: 2H₂(g) + O₂(g) → 2H₂O(g)

Given the standard enthalpies of formation (∆H°f) for H₂, O₂, and H₂O as 0 kJ/mol, 0 kJ/mol, and -285.8 kJ/mol, respectively.

Solution :

To calculate ∆H°, you can use the standard enthalpies of formation:

∆H° = Σ(∆H°f(products)) - Σ(∆H°f(reactants))

∆H° = [2∆H°f(H₂O)] - [2∆H°f(H₂) + ∆H°f(O₂)]

∆H° = [2(-285.8 kJ/mol)] - [2(0 kJ/mol) + 0 kJ/mol]

∆H° = -571.6 kJ/mol