In the reaction: $H_2 + Cl_2 \to 2HCl, \Delta H = -194 \ kJ$. The heat of formation of $HCl$ is ........ $kJ$.

The enthalpy of combustion at $25\,^{\circ}C$ of $H_2$,cyclohexene $(C_6H_{10})$ and cyclohexane $(C_6H_{12})$ are $-241$,$-3800$ and $-3920 \ kJ/mol$ respectively. The heat of hydrogenation of cyclohexene is.....$kJ/mol$.

At $298 \ K$,the enthalpy of fusion of a solid $(X)$ is $2.8 \ kJ \ mol^{-1}$ and the enthalpy of vaporisation of the liquid $(X)$ is $98.2 \ kJ \ mol^{-1}$. The enthalpy of sublimation of the substance $(X)$ in $kJ \ mol^{-1}$ is $.....$ (in nearest integer).

Enthalpy change for a reaction does not depend upon

What is the enthalpy change for the reaction $NaOH_{(aq)} + HCl_{(aq)} \rightarrow NaCl_{(aq)} + H_2O_{(l)}$ called?

The enthalpy of formation of $NH_3$ is $-46 \ kJ \ mol^{-1}$. The enthalpy change for the reaction $2 NH_{3(g)} \longrightarrow N_{2(g)} + 3 H_{2(g)}$ is