$10 \ g$ each of $NH_3, N_2, Cl_2$ and $H_2S$ are expanded isothermally and reversibly at the same temperature. Identify the gas that performs maximum work.

At $25^{\circ} C$,$50 \ g$ of iron reacts with $HCl$ to form $FeCl_2$. The evolved hydrogen gas expands against a constant pressure of $1 \ bar$. The work done by the gas during this expansion is ....... $J$. (Round off to the Nearest Integer) [Given : $R = 8.314 \ J \ mol^{-1} \ K^{-1}$. Assume,hydrogen is an ideal gas] [Atomic mass of $Fe$ is $55.85 \ u$]

At constant volume,$5 \, mol$ of a gas shows an increase in temperature by $3.5 \, K$ upon providing $437.5 \, J$ of heat. What will be the molar heat capacity for the gas at constant pressure in $J \, K^{-1} \, mol^{-1}$?

Match the following:

$A$. Isothermal process	$i$. $q = \Delta U$
$B$. Adiabatic process	$ii$. $W = - P \times \Delta V$
$C$. Isobaric process	$iii$. $W = \Delta U$
$D$. Isochoric process	$iv$. $W = - nRT \ln \left(\frac{v_f}{v_i}\right)$

Assuming the water vapour to be a perfect gas,calculate the internal energy change when $1 \ mol$ of water at $100^{\circ} C$ and $1 \ bar$ pressure is converted to ice at $0^{\circ} C$. Given the enthalpy of fusion of ice is $6.00 \ kJ \ mol^{-1}$ and heat capacity of water is $4.2 \ J \ g^{-1} {\circ} C^{-1}$.

If water vapour is assumed to be a perfect gas,the molar enthalpy change for the vaporisation of $1 \ mol$ of water at $1 \ bar$ and $100^{\circ} C$ is $41 \ kJ \ mol^{-1}$. Calculate the internal energy change when $1 \ mol$ of water is vaporised at $1 \ bar$ pressure and $100^{\circ} C$.