Question

energy diagram
energy
reaction progress
what does line e represent?
energy of the reactants enthalpy of reaction
activation energy (forward) energy of the products

Explanation:

In a chemical reaction energy diagram, the enthalpy of reaction (ΔH) is the difference in energy between products and reactants. Here, line E shows the energy difference between the initial (reactants) and final (products) states. The "energy of reactants" is the initial energy level, "activation energy (forward)" is the energy needed to start the reaction (peak - reactants' energy), and "energy of products" is the final energy level. So E represents the enthalpy of reaction.

Answer:

enthalpy of reaction