What is the change in enthalpy for the following reaction? 
2H2O2(aq)  2H2O(l) + O2(g) 

Given:
H2O: ∆H= -242 kJ
H2O2: ∆H= -609 kJ

A.

-286 kJ

B. 

-572 kJ

C. 

572 kJ

D. 

286 kJ

Respuesta :

The given chemical reaction is:

[tex]2H_{2}O_{2}(aq)---> 2H_{2}O(l)+O_{2}(g)[/tex]

The standard heats of formation of [tex]H_{2}O and H_{2}O_{2}[/tex] are:

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

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

Calculating the change in heat:

Δ[tex]H^{0}_{reaction)[/tex]=∑ΔH[tex]_{f}^{0}(products)[/tex]-∑ΔH[tex]_{f}^{0}(reactants)[/tex]

                         = [{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