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Question

Calculate the enthalpy of reaction for the decomposition of hydrogen peroxide to water and oxygen gas according to the following equation. H2O2(l) ------->H2O(l) + O2(g) Use the following Table for the necessary enthalpies of formation. 

Answer 1

Enthalpies of reaction can be found by summing the enthalpies of formation for the products and subtracting the sum of the enthalpies of the reactants.

In this case ΔH_f^o H2O (l) - ΔH_f^o H2O2 (l) = -285.8 kj/mole - (-187.8 kj/mole) = -98.00 kj/mole