The enthalpy of combustion of methane, graphite, and dihydrogen at 298 K are,

–890.3 kJ mol^-1 , –393.5 kJ mol^-1, and –285.8 kJ mol^-1 respectively.

The enthalpy of formation of CH₄(g) is-

1.  –74.8 kJ mol^-1

2.  –52.27 kJ mol^-1

3.  +74.8 kJ mol^-1

4.  +52.26 kJ mol^-1

The enthalpy of combustion of carbon to CO₂ is –393.5 kJ mol^-1. The amount of heat released upon formation of 35.2 g of CO₂ from carbon and dioxygen gas would be-

1. -393.5 kJ mol^-1

2. -314.8 kJ mol^-1

3. +314.8 kJ mol^-1

4. -320.5 kJ mol^-1

The enthalpy of formation of ${\mathrm{CO}}_{\left(\mathrm{g}\right)},$ ${\mathrm{CO}}_{2\left(\mathrm{g}\right)},$ ${\mathrm{N}}_2{\mathrm{O}}_{\left(\mathrm{g}\right)} , \mathrm{and}$ ${\mathrm{N}}_2{\mathrm{O}}_{4\left(\mathrm{g}\right)}$ $$are

–110 kJ ${\mathrm{mol}}^{-1}$, – 393 kJ ${\mathrm{mol}}^{-1}$, 81 kJ ${\mathrm{mol}}^{-\mathrm{1,}}$ and 9.7 kJ $mo{l}^{-1}$ respectively.

The value of ${∆}_{\mathrm{r}}\mathrm{H}$ for the reaction would be-

${\mathrm{N}}_2{\mathrm{O}}_{4\left(\mathrm{g}\right)}+3{\mathrm{CO}}_{\left(\mathrm{g}\right)}\to {\mathrm{N}}_2{\mathrm{O}}_{\left(\mathrm{g}\right)}+3{\mathrm{CO}}_{2\left(\mathrm{g}\right)}$

$1.$ $-777.7$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$2.$ $$ $+777.7$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$3.$ $$ $+824.9$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$4.$ $-$ $345.4$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$

 ${\mathrm{N}}_2 + 3 {\mathrm{H}}_2 \to 2{\mathrm{NH}}_{3 ;} {∆}_{\mathrm{r}}{\mathrm{H}}^{°} = -92.4 \mathrm{kJ} {\mathrm{mol}}^{-1}$. The standard enthalpy of formation of ${\mathrm{NH}}_3$ gas in the above reaction would be-

The standard enthalpy of the formation of CH₃OH_(l)  from the following data is:

${∆}_{\mathrm{vap}}\mathrm{H}°$ $\left({\mathrm{CCl}}_4\right)$ $=$ $30.5$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
${∆}_{\mathrm{f}}\mathrm{H}°$ $\left({\mathrm{CCl}}_4\right)$ $=$ $-$ $135.5$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
${∆}_{\mathrm{a}}\mathrm{H}°$ $\left(\mathrm{C}\right)$ $=$ $715.0$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
${∆}_{\mathrm{a}}\mathrm{H}°$ $\left({\mathrm{Cl}}_2\right)\hspace{0.17em}=$ $242$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$

The enthalpy change for the reaction

 ${\mathrm{CCl}}_4$ $\left(\mathrm{g}\right)$ $\to$ $\mathrm{C}\left(\mathrm{g}\right)$ $+$ $4\mathrm{Cl}$ $\left(\mathrm{g}\right)$ would be -

$1.$ $326$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$2.$ $1304$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$3.$ $-328$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$
$4.$ $-1304$ $\mathrm{kJ}$ ${\mathrm{mol}}^{-1}$