An exothermic reaction `A rarr B` is spontaneous in the backward direction. What will be the sign of `DeltaS` for the forward reaction ?

Explanation

To determine the sign of \( \Delta S \) (the change in entropy) for the forward reaction \( A \rightarrow B \), we need to analyze the information given in the question.

### Step-by-Step Solution:

1. **Understanding the Reaction**: The reaction \( A \rightarrow B \) is exothermic, meaning it releases heat. In an exothermic reaction, the enthalpy change \( \Delta H \) is negative (\( \Delta H < 0 \)).

2. **Spontaneity of the Backward Reaction**: The question states that the reaction is spontaneous in the backward direction (\( B \rightarrow A \)). For a reaction to be spontaneous, the Gibbs free energy change \( \Delta G \) must be negative (\( \Delta G < 0 \)).

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