Question

The change in enthalpy is the change in heat energy of a reaction and is calculated by (Hint: Hess' Law): Group of answer choices

a. Sum of reactant enthalpies plus the sum of product enthalpies
b. Sum of reactant enthalpies minus the sum of product enthalpies
c. Sum of product enthalpies times the sum of reactant enthalpies
d. Sum of product enthalpies minus the sum of reactant enthalpies

Answer 1

d. Sum of product enthalpies minus the sum of reactant enthalpies

Step-by-step explanation:

The standard enthalpy change of a reaction (ΔH°rxn) can be calculated using the following expression:

ΔH°rxn = ∑n(products) × ΔH°f(products) - ∑n(reactants) × ΔH°f(reactants)

where,

ni are the moles of products and reactants

ΔH°f(i) are the standard enthalpies of formation of products and reactants