Question

In the burning ethanol, how do the molecular energy levels of reactants compare to products?

a) Reactants have higher energy
b) Products have higher energy
c) Reactants and products have equal energy
d) Energy levels are not affected

Answer 1

In burning ethanol, the reactants have a higher molecular energy level than the products, characterizing the reaction as exothermic with energy being released. An energy barrier known as activation energy must be first overcome, but ultimately, the reactants transition to products and release energy.

Step-by-step explanation:

In the context of burning ethanol, the molecular energy levels of reactants compared to products are such that the reactants have higher energy than the products. This is indicative of an exothermic reaction, where energy is released into the surroundings.

Additionally, the fact that a reaction proceeds suggests that it has overcome the activation energy barrier, which is the minimum amount of energy required to initiate the reaction. Although the activation energy is positive, meaning it is energy that needs to be supplied, the reactants ultimately transition to products with lower potential energy, thus releasing energy overall.

During the course of the reaction, energy is used to break bonds between the reactant particles, which does not necessarily increase the kinetic energy of the system's particles but serves to facilitate the chemical transformation. The energy diagram typically shows the reactants on the left at a higher energy level, a peak representing the activated complex or transition state, and the products at a lower energy level on the right.