Question

Imagine a graph The x-axis is labeled "Time" and is measured in seconds, and the y-axis is labeled "Potential Energy and is

measured in kilojoules. The slope starts at 0 seconds with a plateau at 25 kJ. This plateau is labeled "Reactants" The slope
then rises to a peak labeled "Activation Energy" at 78 kJ. Finally the slope drops to a plateau at 14 kJ and is labeled
"Products"
What does the graph described above represent?
(1 point)
an exothermic reaction.
O an endothermic reaction
O a phase change graph
O rate of Reaction graph

Answer 1

The described graph represents a reaction profile for a chemical reaction. The plateau at 25 kJ represents reactants, the peak at 78 kJ is the activation energy, and the plateau at 14 kJ represents products. The nature of the reaction (exothermic or endothermic) is not specified.

The graph described represents a reaction profile or energy profile diagram for a chemical reaction. The key features on the graph include:

1. **Reactants Plateau (25 kJ):** This represents the initial state of the reactants, where they have a certain amount of potential energy.

2. **Activation Energy Peak (78 kJ):** This is the energy barrier that must be overcome for the reaction to proceed. It is the difference in energy between the reactants and the transition state of the reaction.

3. **Products Plateau (14 kJ):** This represents the final state of the products, where they have a certain amount of potential energy.

Based on the information provided, the graph does not specify whether the overall reaction is exothermic or endothermic. However, you can make an inference based on the position of the reactants and products. If the products' plateau is lower than the reactants' plateau, it would be an exothermic reaction (energy is released). If the products' plateau is higher than the reactants' plateau, it would be an endothermic reaction (energy is absorbed).

So, the correct answer would be:

- If the products plateau is lower than the reactants plateau: **an exothermic reaction.**

- If the products plateau is higher than the reactants plateau: **an endothermic reaction.**