If the enthalpies of atomization of methane and ethane are respectively $320 \ cal$ and $360 \ cal$,then the bond energy of the $C-C$ bond is......$cal$.

From the following data,the enthalpy of vaporization of liquid water in $KJ \, mol^{-1}$ will be:
$H_2(g) + 1/2 O_2(g) \rightarrow H_2O(l); \Delta H = -285.77 \, KJ \, mol^{-1}$
$H_2(g) + 1/2 O_2(g) \rightarrow H_2O(g); \Delta H = -241.84 \, KJ \, mol^{-1}$

The enthalpy changes for the following processes are listed below:

$Cl_{2(g)} \rightarrow 2Cl_{(g)}$	$242.3 \ kJ \ mol^{-1}$
$I_{2(g)} \rightarrow 2I_{(g)}$	$151.0 \ kJ \ mol^{-1}$
$ICl_{(g)} \rightarrow I_{(g)} + Cl_{(g)}$	$211.3 \ kJ \ mol^{-1}$
$I_{2(s)} \rightarrow I_{2(g)}$	$62.76 \ kJ \ mol^{-1}$

Given that the standard states for iodine and chlorine are $I_{2(s)}$ and $Cl_{2(g)}$,the standard enthalpy of formation for $ICl_{(g)}$ is : ............... $kJ \ mol^{-1}$

The heat of combustion of carbon is $-393.5 \ kJ / mol$. The heat released upon the formation of $35.2 \ g$ of $CO_{2}$ from carbon and oxygen gas is

Choose the reaction$(s)$ from the following options,for which the standard enthalpy of reaction is equal to the standard enthalpy of formation.
$(1)$ $\frac{3}{2} O_{2(g)} \rightarrow O_{3(g)}$
$(2)$ $\frac{1}{8} S_{8(s)} + O_{2(g)} \rightarrow SO_{2(g)}$
$(3)$ $2 H_{2(g)} + O_{2(g)} \rightarrow 2 H_2O_{(l)}$
$(4)$ $2 C_{(g)} + 3 H_{2(g)} \rightarrow C_2H_{6(g)}$

Which of the following statements is correct about the heat of combustion?