Question

enthalpy diagram
reaction progress
energy and enthalpy statements
1 the net enthalpy is represented by i
2 the net enthalpy is represented by ii
3 the activation energy has a positive value.
4 the activation energy has a negative value.
5 the net enthalpy has a positive value.
6 the net enthalpy has a negative value.
numerical response

1. the statements that apply to the forward reaction represented by the enthalpy diagram above are numbered __, , and __. (record all three digits of your answer in any order in the numerical - response section on the answer sheet.)

Explanation:

Step1: Define net - enthalpy and activation energy

Net enthalpy ($\Delta H$) is the difference in enthalpy between products and reactants. Activation energy ($E_a$) is the energy barrier that must be overcome for the reaction to proceed.

Step2: Analyze the enthalpy diagram

The height from the reactants to the peak of the curve is the activation energy. Since the peak is above the reactants, the activation energy has a positive value (Statement 3). The net enthalpy is the difference in enthalpy between products and reactants. Here, the products have a higher enthalpy than the reactants, so the net enthalpy has a positive value (Statement 5). The net enthalpy is represented by the vertical distance between the products and reactants, which is II (Statement 2).

Answer:

2, 3, 5