Question

Hess' law is applicable for determination of enthalpy of

• A. Reaction
• B. Formation
• C. Transition
• D. All of the above

Answer 1

The correct option is D All of the above

According to the Hess' law of constant heat summation total enthalpy change for the net reaction is sum of all enthalpy changes of individual steps.Or, the standard enthalpy of a reaction, which takes place in several steps, is the sum of standard enthalpies of intermediate reactions. Hence it is applicable for all.
$\Delta H=\Delta H_1+\Delta H_2+\Delta H_3+....$
It can be used to determine heat of formation, transition, reaction, hydration, etc.