What is the enthalpy change for $2H_2O_{2(l)} \to 2H_2O_{(l)} + O_{2(g)}$ if the heats of formation of $H_2O_{2(l)}$ and $H_2O_{(l)}$ are $-188 \ kJ/mol$ and $-286 \ kJ/mol$ respectively?

Find the value $\Delta H_f^o[NH_{3(g)}]$ if $\Delta H_r$ for the reaction $N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$ is $-\,183.6 \ kJ/mol$ of $N_{2(g)}$.

The heat of reaction does not depend upon

The formation enthalpies,$\Delta H_{f}^{\ominus}$ for $H_{(g)}$ and $O_{(g)}$ are $220.0$ and $250.0 \ kJ \ mol^{-1}$,respectively,at $298.15 \ K$,and $\Delta H_{f}^{\ominus}$ for $H_2O_{(g)}$ is $-242.0 \ kJ \ mol^{-1}$ at the same temperature. The average bond enthalpy of the $O-H$ bond in water at $298.15 \ K$ is $.......... \ kJ \ mol^{-1}$ (nearest integer).

Which substance has a standard molar enthalpy of formation equal to zero at $298 \ K$?

Given below are two statements: One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$
Assertion $(A)$: Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always $-57 \ kJ \ mol^{-1}$.
Reason $(R)$: Enthalpy of neutralisation is the amount of heat liberated when one mole of $H^{+}$ ions furnished by acid combine with one mole of $OH^{-}$ ions furnished by base to form one mole of water.
In the light of the above statements,choose the correct answer from the options given below.