Use the table to answer the question: Which statement about the change in bond energy of this reaction is correct?

Question

Table showing a water molecule being broken into hydrogen and oxygen and the bond energies associated with this reaction.

(1 point)
Responses

The reaction is exothermic because the energy of each bond in the reactants is greater than the energy of a bond in the products.
The reaction is exothermic because the energy of each bond in the reactants is greater than the energy of a bond in the products.

The reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products.
The reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products.

The reaction is exothermic because the total bond energy of the reactants is less than the total bond energy of the products.
The reaction is exothermic because the total bond energy of the reactants is less than the total bond energy of the products.

The reaction is endothermic because the energy of each bond in the reactants is less than the energy of a bond in the products.

Answer 1

To determine whether the reaction is exothermic or endothermic based on bond energies, we use the following principles:

• A reaction is exothermic if the total bond energy of the products is less than the total bond energy of the reactants. This means more energy is released when new bonds are formed in the products compared to the energy required to break the bonds in the reactants.

• A reaction is endothermic if the total bond energy of the products is greater than the total bond energy of the reactants. This indicates that more energy is required to break the bonds in the reactants than is released when new bonds are formed in the products.

In this case, since the reaction involves breaking a water molecule into hydrogen and oxygen, we can infer that breaking these bonds requires energy, and if the products have a higher total bond energy, the reaction absorbs energy and is endothermic.

Given the statements provided:

1. The first statement describes the reaction as exothermic because the reactants have higher bond energy than the products, which is incorrect if the total bond energy of the products is actually greater.

2. The second statement claims the reaction is endothermic because the total bond energy of reactants is greater than that of products. This supports the endothermic descriptor.

3. The third and fourth statements incorrectly describe the relationship between the reactants and products in terms of their bond energy.

Since the correct interpretation based on the concepts of bond energies is that the reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products, the correct response is:

The reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products.