Question

In an exothermic reaction, heat is evolved, and system loses heat to the surrounding. For such system

• A. $q_p$ will be negative
• B. ${△}_{r}H$ will be positive
• C. $q_p$ will be positive
• D. ${△}_{r}H$ will be negative

Answer 1

Answer: (A), (D)

${△}_{r}H$ will be negative

For exothermic reaction, enthalpy change is negative$({△}_{r}H$ is a negative).

$q_p={△}_{r}H$ at constant pressure

$△q_p$ will also be negative

Since in the question it is mentioned that it is an exothermic reaction.

$\therefore q_p={△}_{r}H=$negative value

So, options (A) and (B) are correct.