Given the following thermochemical equations:
$(i) S_{(s)} + \frac{3}{2} O_{2(g)} \rightarrow SO_{3(g)} + 2x \, kcal$
$(ii) SO_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow SO_{3(g)} + y \, kcal$
Find the heat of formation of $SO_{2(g)}$.

At $25^{\circ} C$ and $1 \, atm$ pressure,the enthalpy of combustion of benzene$_{(l)}$ and acetylene$_{(g)}$ are $-3268 \, kJ \, mol^{-1}$ and $-1300 \, kJ \, mol^{-1}$,respectively. The change in enthalpy for the reaction $3 C_2H_{2(g)} \rightarrow C_6H_{6(l)}$ is $..... \, kJ \, mol^{-1}$.

The quantity of heat (in $J$) required to raise the temperature of $1.0 \, kg$ of ethanol from $293.45 \, K$ to the boiling point and then change the liquid to vapor at that temperature is closest to
[Given,boiling point of ethanol $351.45 \, K$. Specific heat capacity of liquid ethanol $2.44 \, J \, g^{-1} \, K^{-1}$. Latent heat of vaporisation of ethanol $855 \, J \, g^{-1}$ ]

Find the enthalpy of neutralisation of $NH_4OH$ and $HCN$ in aqueous solution if the enthalpy of ionisation of $NH_4OH$ and $HCN$ are $7 \ kJ/mol$ and $8 \ kJ/mol$ respectively. Also,the enthalpy of neutralisation of $H^{+}$ and $OH^{-}$ is $-57.3 \ kJ/mol$.

For the following reaction occurring in automobiles,the values of $\Delta H, \Delta S, \text{and } \Delta G$ are respectively:
$2C_8H_{18(g)} + 25O_2(g) \rightarrow 16CO_2(g) + 18H_2O(g)$

The reaction $NH_2CN_{(s)} + \frac{3}{2}O_{2(g)} \to N_{2(g)} + CO_{2(g)} + H_2O_{(l)}$ is carried out in a bomb calorimeter. The heat evolved is $743 \ kJ \ mol^{-1}$. Calculate the value of $\Delta H$ at $300 \ K$ in $kJ \ mol^{-1}$.