Assertion : `DeltaH` for an exothermic reaction is negative nad for an endothermic reaction is positive.
Reason : Enthalpy is an extensive property.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

B

Explanation

In an exothermic reaction, heat is evolved and system loses heat to the surrounding. Therefore, `q_(p)` will be negative and hence `DeltaH` will be negative `[because q_(p)=H_(2)-H_(1)=DeltaH]`. Similarly, in an endothermic reaction heat is absorbed, `q_(b)` is positive hence, `DeltaH` will be positive.