For isothermal expansion of an ideal gas, the correct combination of the thermodynamic parameters will be

$7 \ g$ of $N_{2(g)}$ at $27 \ ^oC$ is expanded reversibly and isothermally from an initial pressure of $0.5 \ MPa$ to a final pressure of $0.1 \ MPa$. Determine the approximate work done $[\ln \ 5 = 1.6]$ ..... $J$

For which of the following thermodynamic processes is $\Delta U = 0$?

$X \, g$ 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 $= 4.184 \, J / g \cdot K$]

Expansion of $1$ $mol$ of an ideal gas takes place from $2$ $L$ to $8$ $L$ at $300$ $K$ against a constant external pressure of $1$ $atm$. Calculate $\Delta S_{total}$ in $J$ $K^{-1}$ $mol^{-1}$.
(Given: $R = 8.3$ $J$ $K^{-1}$ $mol^{-1}$,$1$ $L$ $atm = 100$ $J$,$\ln 2 = 0.693$) (in $.5$)

For the complete combustion of ethanol,$C_2H_5OH_{(l)} + 3O_{2(g)} \rightarrow 2CO_{2(g)} + 3H_2O_{(l)}$,the amount of heat produced as measured in a bomb calorimeter is $1364.47 \ kJ \ mol^{-1}$ at $25 \ ^oC$. Assuming ideality,the enthalpy of combustion,$\Delta_cH$,for the reaction will be: $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$ .....$kJ \ mol^{-1}$