Which of the following correctly describes the net energy change during a reaction?
A. The net change in energy is negative for endothermic reactions where energy is required.
B. The net change in energy is positive for endothermic reactions where energy is required.
C. The net change in energy is positive for endothermic reactions where energy is released.
D. The net change in energy is positive for exothermic reactions where energy is required.
the answer should be B
The correct answer is:
D. The net change in energy is positive for exothermic reactions where energy is required.
To determine the correct answer, we need to understand the different types of reactions and the corresponding changes in energy.
An endothermic reaction is a reaction that absorbs energy from its surroundings. In this type of reaction, the reactants have lower energy than the products, so energy is required to break the bonds in the reactants and form the bonds in the products. Therefore, endothermic reactions have a positive net change in energy.
On the other hand, an exothermic reaction is a reaction that releases energy to its surroundings. In this type of reaction, the reactants have higher energy than the products, so energy is released as the bonds in the reactants break and the bonds in the products form. Therefore, exothermic reactions have a negative net change in energy.
Let's analyze the given options:
A. The net change in energy is negative for endothermic reactions where energy is required. - This statement is incorrect because the net change in energy for endothermic reactions is positive, not negative.
B. The net change in energy is positive for endothermic reactions where energy is required. - This statement is correct. Endothermic reactions require energy input and have a positive net change in energy.
C. The net change in energy is positive for endothermic reactions where energy is released. - This statement is incorrect because endothermic reactions release energy, not absorb it.
D. The net change in energy is positive for exothermic reactions where energy is required. - This statement is incorrect. Exothermic reactions release energy and have a negative net change in energy.
Based on the explanations above, the correct answer is B. The net change in energy is positive for endothermic reactions where energy is required.