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

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

Thermodynamics

Solution:

In an exothermic reaction, heat is evolved and system loses heat to the surroundings. Therefore, $q_p$ will be negative and hence $\Delta H$ will be negative $[\Delta q_p = H_2 - H_1 = \Delta H]$. Similarly, in an endothermic reaction heat is absorbed, $q_p$ is positive hence, $\Delta H$ will be positive.