The heat of formation of $H_2O$ is $-286 \, kJ/mol$ and $H_2O_2$ is $-188 \, kJ/mol$. The enthalpy change for the reaction $2H_2O_2 \to 2H_2O + O_2$ is......$kJ$.

Average $C-H$ bond energy is $416 \ kJ \ mol^{-1}$. Which of the following is correct?

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.....$kJ/mol$.

For the reaction $2H_2O_2(\ell) \to 2H_2O(\ell) + O_2(g)$,what is the enthalpy change? Given that the heats of formation of $H_2O_2(\ell)$ and $H_2O(\ell)$ are $-188 \, kJ/mol$ and $-286 \, kJ/mol$ respectively.

The standard enthalpy of atomization of ethane according to the equation $C_2H_{6(g)} \rightarrow 2C_{(g)} + 6H_{(g)}$ is $622 \ kJ \ mol^{-1}$. If the standard mean $C-H$ bond dissociation enthalpy is $90 \ kJ \ mol^{-1}$,the standard mean dissociation enthalpy of the $C-C$ bond (in $kJ \ mol^{-1}$) is:

The $\Delta H_f^o$ for $CO_{2(g)}$,$CO_{(g)}$ and $H_2O_{(g)}$ are $-393.5$,$-110.5$ and $-241.8 \ kJ \ mol^{-1}$ respectively. The standard enthalpy change (in $kJ$) for the reaction $CO_{2(g)} + H_{2(g)} \to CO_{(g)} + H_2O_{(g)}$ is