$4 \ g$ of $NH_4NO_3$ were dissolved in $196 \ g$ of water at constant pressure in a calorimeter with a heat capacity of $160 \ J \ K^{-1}$. The temperature fell by $1.3 \ K$. The specific heat of the solution is $4.2 \ J \ K^{-1} \ g^{-1}$. The enthalpy of solution of $NH_4NO_3$ is $......$ $kJ \ mol^{-1}$.

The entropy versus temperature plot for phases $\alpha$ and $\beta$ at $1 \ bar$ pressure is given. $S_T$ and $S_0$ are entropies of the phases at temperatures $T$ and $0 \ K$,respectively.
The transition temperature for $\alpha$ to $\beta$ phase change is $600 \ K$ and $C_{p, \beta} - C_{p, \alpha} = 1 \ J \ mol^{-1} \ K^{-1}$. Assume $(C_{p, \beta} - C_{p, \alpha})$ is independent of temperature in the range of $200$ to $700 \ K$. $C_{p, \alpha}$ and $C_{p, \beta}$ are heat capacities of $\alpha$ and $\beta$ phases,respectively.
$(1)$ The value of entropy change,$S_{\beta} - S_{\alpha}$ (in $J \ mol^{-1} \ K^{-1}$),at $300 \ K$ is. . . . . . .
$(2)$ The value of enthalpy change,$H_{\beta} - H_{\alpha}$ (in $J \ mol^{-1}$),at $300 \ K$ is.
[Use : $\ln 2 = 0.69$,Given : $S_{\beta} - S_{\alpha} = 0$ at $0 \ K$]

Calculate $\Delta H^{\circ}$ for the reaction, $Na_2O_{(s)} + SO_{3(g)} \longrightarrow Na_2SO_{4(s)}$, given the following reactions:
$(A) \ Na_{(s)} + H_2O_{(l)} \longrightarrow NaOH_{(s)} + \frac{1}{2}H_{2(g)} \quad \Delta H^{\circ} = -146 \ kJ$
$(B) \ Na_2SO_{4(s)} + H_2O_{(l)} \longrightarrow 2NaOH_{(s)} + SO_{3(g)} \quad \Delta H^{\circ} = +418 \ kJ$
$(C) \ 2Na_2O_{(s)} + 2H_{2(g)} \longrightarrow 4Na_{(s)} + 2H_2O_{(l)} \quad \Delta H^{\circ} = +259 \ kJ$

For the following combustion reaction occurring in an automobile: $2C_{8}H_{18(g)} + 25O_{2(g)} \to 16CO_{2(g)} + 18H_{2}O_{(g)}$,what are the signs of $\Delta H$,$\Delta S$,and $\Delta G$?

$A$ cylinder of gas supplied by Bharat Petroleum is assumed to contain $14 \ kg$ of butane. If a normal family requires $20,000 \ kJ$ of energy per day for cooking,how many days will the butane gas in the cylinder last? ($\Delta H_c$ of $C_4H_{10} = -2658 \ kJ/mole$)

How much heat in $KJ$ is released during the combustion of $112 \ L$ of water gas at $S.T.P.$? (Water gas is an equimolar mixture of $H_2$ and $CO$)
$H_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow H_2O_{(g)}; \Delta H = -241.8 \ KJ$
$CO_{(g)} + \frac{1}{2} O_{2(g)} \rightarrow CO_{2(g)}; \Delta H = -283 \ KJ$