Question

The energy diagram of a reaction $P+Q\to R+S$ is given. What are $A$ and $B$ in the graph?

• A. $A\to$ activation energy, $B\to$ heat of reaction
• B. $A\to$ threshold energy, $B\to$ heat of reaction
• C. $A\to$ heat of energy, $B\to$ activation reaction
• D. $A\to$ potential energy, $B\to$ energy of reaction

Answer 1

Answer: (A)

$A\to$ activation energy, $B\to$ heat of reaction

The heat of reaction is given by:-

$△H={Ea}_f-{Ea}_b$.

Let's suppose $O$ is the highest point of the curve then $RO$ is forward activation energy and $PO$ is backward activation energy and the difference of these two will give the heat of reaction, [Indicated in the figure]

Hence, the correct answer is option $\text{A}$.