For the reaction:
$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}$;
$\Delta_r H_{300} = -212.7 \ Kcal/mol$.
The absolute value of $\Delta_r U_{300}^o$ for this reaction is ....... $Kcal/mol$ $(R = 2 \ cal/mol-K)$.

When $1 \ g$ of $NH_4NO_3$ is decomposed in a bomb calorimeter,the temperature of the calorimeter increases by $6.12 \ K$. If the heat capacity of the system is $1.23 \ kJ/K$,the molar enthalpy of decomposition of $NH_4NO_3$ is ........ $kJ/mol$.

For the following reaction $Fe_2O_{3(s)} + 3 CO_{(g)} \longrightarrow 2 Fe_{(s)} + 3 CO_{2(g)}$,$\Delta H^{\circ} = -29.8 \ kJ$ and $\Delta S^{\circ} = 15 \ JK^{-1}$. What is the value of $\Delta S_{\text{total}}$ at $298 \ K$ (in $JK^{-1}$)?

Match the following:

List-$I$	List-$II$
$(A) \Delta U = W_{ad}$	$I.$ Isothermal reversible expansion
$(B) \Delta U = q - W$	$II.$ Wall is adiabatic
$(C) \Delta U = -q$	$III.$ Thermally conducting walls
$(D) \Delta U = 0$	$IV.$ Isolated system
	$V.$ Closed system

The correct answer is

Calculate $\Delta H$ when $2 \ moles$ of solid benzoic acid undergo complete combustion at $300 \ K$ if $C_6H_5COOH_{(s)} + \frac{15}{2} O_{2(g)} \rightarrow 7CO_{2(g)} + 3H_2O_{(l)}$,$\Delta U_{reaction} = -750 \ kJ/mole$ [$R = 8 \ J/mole \cdot K$].

$X \, g$ of ice at $0^{\circ} C$ is added to $340 \, g$ of water at $20^{\circ} C$. The final temperature of the resultant mixture is $5^{\circ} C$. The value of $X$ (in $g$) is closest to:
[Heat of fusion of ice $= 333 \, J / g$; specific heat of water $= 4.184 \, J / g \cdot K$]