Consider the following reaction:

$H_2(g)+\frac{1}{2}{O}_2(g)longrightarrow{H}_{2}O(g)$

$H=-241\mathrm{.}8kJ$

a$)$ Sketch the energy profile diagram of the above reaction.

b$)$ Which enthalpy is larger, that of the reactants or the product?

c$)$ For the reaction,

$2H_{2}O(g)longrightarrow2H_2(g)+O_2(g)$

what is the enthalpy change under the same conditions?