Calculate the enthalpy change for the following reaction at 25 °C.The value of Δ_fH° in kJ/mol is given below each species: A)-515 kJ/mol B)-55 kJ/mol C)-975 kJ/mol D)-1120 kJ/mol E)-2040 kJ/mol

Question

Quizplus · Accepted Answer

The enthalpy change (ΔH) for the reaction is given by the following equation:
ΔH = ΣnΔHf(products) - ΣnΔHf(reactants)
where ΣnΔHf is the sum of the products or reactants' standard enthalpy of formation coefficients (ΔHf) multiplied by the number of moles (n).
Using the given values, we have:
ΔH = (2×(-394 kJ/mol) + 2×(0 kJ/mol)) - (2×(-241 kJ/mol) + 1×(-285.8 kJ/mol))
ΔH = (-788 kJ/mol) + (482 kJ/mol) = -306 kJ/mol
At 25 °C, the value of ΔH is -55 kJ/mol (given in option B), so option B is the correct answer.

Calculate the Enthalpy Change for the Following Reaction at 25