For the reaction $F_2 + 2HCl \rightarrow 2HF + Cl_2$,the $\Delta H^o$ is $-352.8 \ kJ$. If the $\Delta H_f^o$ for $HF$ is $-268.3 \ kJ \ mol^{-1}$,then the $\Delta H_f^o$ for $HCl$ will be . . . . . . $kJ \ mol^{-1}$.

The enthalpy of reaction for the reaction: $2 H_{2(g)} + O_{2(g)} \to 2 H_{2}O_{(l)}$ is $\Delta_{r}H^{\theta} = -572 \ kJ \ mol^{-1}$. What will be the standard enthalpy of formation of $H_{2}O_{(l)}$?

If the ratio of the enthalpy of formation of $CO_2$ and $SO_2$ is $4:3$ and the enthalpy of formation of $CS_2$ is $26 \ kcal/mol$,then what will be the enthalpy of formation of $SO_2(g)$ based on the following reaction?
$CS_2(l) + 3O_2(g) \to CO_2(g) + 2SO_2(g)$

The enthalpy change for the transition of carbon from diamond to graphite is $\Delta H = -453.5 \ \text{cal}$. What does this indicate?

The standard enthalpy of formation of $NH_3$ is $-46.0 \ kJ \ mol^{-1}.$ If the enthalpy of formation of $H_2$ from its atoms is $-436 \ kJ \ mol^{-1}$ and that of $N_2$ is $-712 \ kJ \ mol^{-1},$ the average bond enthalpy of $N-H$ bond in $NH_3$ is ................ $kJ \ mol^{-1}$

$S + \frac{3}{2} O_2 \to SO_3 + 2x \ kcal$
$SO_2 + \frac{1}{2} O_2 \to SO_3 + y \ kcal$
Find out the heat of formation of $SO_2$.