Assertion: Δ H for an exothermic reaction is negative and for an endothermic reaction is positive. Reason: Enthalpy is an extensive property.

Question

Assertion: Δ H for an exothermic reaction is negative and for an endothermic reaction is positive. Reason: Enthalpy is an extensive property. (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

Tardigrade Admin · Accepted Answer

In an exothermic reaction, heat is evolved and system loses heat to the surroundings. Therefore, qp will be negative and hence Δ H will be negative [Δ qp = H2 - H1 = Δ H]. Similarly, in an endothermic reaction heat is absorbed, qp is positive hence, Δ H will be positive.

Q. Assertion : ΔH for an exothermic reaction is negative and for an endothermic reaction is positive. Reason : Enthalpy is an extensive property.

If both assertion and reason are true and reason is the correct explanation of assertion

If both assertion and reason are true but reason is not the correct explanation of assertion

If assertion is true but reason is false

If both assertion and reason are false

In an exothermic reaction, heat is evolved and system loses heat to the surroundings. Therefore, qp​ will be negative and hence ΔH will be negative [Δqp​=H2​−H1​=ΔH]. Similarly, in an endothermic reaction heat is absorbed, qp​ is positive hence, ΔH will be positive.

Q. Assertion : $Δ H$ for an exothermic reaction is negative and for an endothermic reaction is positive.
Reason : Enthalpy is an extensive property.