Question

$△S_{surr}$ for an exothermic reaction is

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

Answer 1

The correct option is D may be positive or negative

Heat is released in an exothermic process which increases the entropy of surroundings. When entropy of the system is positive, overall entropy change is also positive. In some exothermic reactions, entropy of system may decrease. For an exothermic reaction increased disorder gives entropy change positive $\Delta S>0$ and the process will be spontaneous. If the disorder decreases entropy change will be negative $\Delta S<0$ and spontaneity depends on temperature.