The heat of combustion of carbon monoxide at constant volume and at $17 \ ^oC$ is $-283.3 \ kJ$. Calculate its heat of combustion at constant pressure in $kJ$. $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$ (in $.5$)

Given that $C_{(g)} + 4H_{(g)} \longrightarrow CH_{4(g)}$,$\Delta H^{\circ} = -1665 \ kJ$. What is the bond energy per mole of $C-H$ bond?

Standard molar enthalpy of formation of $CO_2$ is equal to

Bond enthalpies of $A_{2}$,$B_{2}$ and $AB$ are in the ratio $2:1:2$. If the enthalpy of formation of $AB$ is $-100 \ kJ \ mol^{-1}$,the bond enthalpy of $B_{2}$ is:

Consider the following data :
Heat of formation of $CO_{2(g)} = -393.5 \ kJ \ mol^{-1}$
Heat of formation of $H_2O_{(l)} = -286.0 \ kJ \ mol^{-1}$
Heat of combustion of benzene $= -3267.0 \ kJ \ mol^{-1}$
The heat of formation of benzene is $........... \ kJ \ mol^{-1}$. $(Nearest \ integer)$

$CuSO_{4(s)} + 5 H_2O_{(\ell)} \rightarrow CuSO_4 \cdot 5 H_2O_{(s)} ; \Delta H = -x \ kJ$. The value of $\Delta H$ represents: