Suppose a pair of chemical compounds A and B can react in two different ways:
Reaction 1 gives product C.
Reaction 2 gives product D.
The following facts are known about the two reactions:
• Both reactions are endothermic, but the heat of reaction of Reaction #1 is larger.
• If a reaction vessel is charged ("filled") with A and B, then at first C is produced faster than D.
Use these facts to sketch a qualitative reaction energy diagram for both reactions.
Note: because these sketches are only qualitative, the energies don't have to be exact. They only have to have the right relationship to each other. For example, if one energy is less than another, that fact should be clear in your sketch.
The reaction energy diagram for Reaction 1 would have a higher initial energy of activation (EA1) compared to Reaction 2, indicating that more energy is required for the reaction to proceed. The energy released in the reaction (ΔH1) would be higher for Reaction 1, showing that more heat is absorbed during the reaction compared to Reaction 2. This would result in a higher energy of the products (C) for Reaction 1 compared to Reaction 2.
The reaction energy diagram for Reaction 2 would have a lower initial energy of activation (EA2) compared to Reaction 1, indicating that less energy is required for the reaction to proceed. The energy released in the reaction (ΔH2) would be lower for Reaction 2, showing that less heat is absorbed during the reaction compared to Reaction 1. This would result in a lower energy of the products (D) for Reaction 2 compared to Reaction 1.
Overall, the reaction energy diagram for Reaction 1 would have higher energy levels for all components compared to Reaction 2, reflecting the fact that Reaction 1 has a larger heat of reaction and is more endothermic than Reaction 2.