Question

What is the change in enthalpy for the following reaction? 

Answer 1

The given chemical reaction is:

$2H_{2}O_{2}(aq)---> 2H_{2}O(l)+O_{2}(g)$

The standard heats of formation of $H_{2}O and H_{2}O_{2}$ are:

Δ$H_{f}^{0}(H_{2}O$) = -285.8kJ/mol[/tex]

Δ$H_{f}^{0}(H_{2}O_{2}$) = -187.6 kJ/mol[/tex]

Calculating the change in heat:

Δ$H^{0}_{reaction)$=∑ΔH$_{f}^{0}(products)$-∑ΔH$_{f}^{0}(reactants)$

                         = [{2 * (-285.8 kJ/mol)} -{2*(-187.6 kJ/mol)}]

                          = -196.4 kJ/mol

Therefore, the change in enthalpy for the given reaction is -196.4 kJ/mol