`Delta S_("surr")` for an exothermic reaction is

Options

A. always positive
B. always negative
C. zero
D. may be positive or negative

Explanation

To determine the change in entropy of the surroundings (`ΔS_surr`) for an exothermic reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Exothermic Reactions**:
- In an exothermic reaction, heat is released into the surroundings. This means that the enthalpy change (`ΔH`) for the reaction is negative.

2. **Formula for Change in Entropy of Surroundings**:
- The change in entropy of the surroundings can be calculated using the formula:
\[ ΔS_{surr} = -\frac{ΔH}{T} \]
where `ΔH` is the change in enthalpy of the system and `T` is the temperature in Kelvin.

3. **Substituting Values**:
- Since we are dealing with an exothermic reaction, `ΔH` is negative. Let's denote `ΔH` as a negative value (e.g., `ΔH = -x` where `x` is a positive number).
- Substituting this into the formula gives:
\[ ΔS_{surr} = -\frac{-x}{T} = \frac{x}{T} \]

4. **Conclusion**:
- Since `x` is positive and `T` is always positive (as temperature cannot be negative), `ΔS_{surr}` will also be positive.
- Therefore, the change in entropy of the surroundings for an exothermic reaction is positive.

### Final Answer:
**ΔS_surr for an exothermic reaction is positive.**