Question

Which expression represents the ∆H for a chemical reaction in terms of the potential energy, PE, of its products and reactants?

A) PE of products + PE of reactants
B) PE of products – PE of reactants
C) PE of reactants × PE of products
D) PE of products ÷ PE of reactants
E) PE of reactants – PE of products

Answer 1

What does expert ratified mean?

Step-by-step explanation:

Answer 2

The answer is the option B) PE of products - PE of reactants.

This is, the change of energy, in the form of heat, ΔH, for a chemical reaction is the potential energy of products less the potential energy of reactants: ΔH = PE products - PE reactants.

Note that this leads to:

1) when the potential energy increases, PE of products - PE of reactants > 0 => ΔH > 0, =>the reaction is absorbing energy and it is endothermic;

2) when potential energy decreases PE of products - PE of reactants < 0 => ΔH < 0, the reaction is releasing energy and it is exothermic.

Those are terms very used in chemistry and thermodynamics.