Question

Consider the potential energy diagram shown below. This graph shows the chemical potential energy in a reaction system over time. The y-axis is potential energy in kilojoules. The x-axis is the reaction progress, or time.
Does this graph represent an endothermic or an exothermic reaction? Explain your answer.

What is the enthalpy change, ΔH, for this reaction? Show your work.

What is the activation energy, Ea, for this reaction? Show your work.

PLEASE GIVE FULL ANSWERS

Answer 1

Answer:

A. Endothermic reaction.

B. +150KJ.

C. 250KJ.

Explanation:

A. The graph represents endothermic reaction because the heat of the product is higher than the heat of the reactant.

B. Determination of the enthalpy change, ΔH for the reaction. This can be obtained as follow:

Heat of reactant (Hr) = 50KJ

Heat of product (Hp) = 200KJ

Enthalphy change (ΔH) =..?

Enthalphy change = Heat of product – Heat of reactant.

ΔH = Hp – Hr

ΔH = 200 – 50

ΔH = +150KJ

Therefore, the enthalphy change for the reaction is +150KJ

C. The activation energy for the reaction is the energy at the peak of the diagram.

From the diagram, the activation energy is 250KJ.