$10 \ g$ 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.

An ideal gas undergoes a reversible isothermal expansion from state $I$ to state $II$ followed by a reversible adiabatic expansion from state $II$ to state $III$. The correct plot$(s)$ representing the changes from state $I$ to state $III$ is(are)
($p$ : pressure,$V$ : volume,$T$ : temperature,$H$ : enthalpy,$S$ : entropy)

For the reaction $Br_{2(l)} + Cl_{2(g)} \rightarrow 2BrCl_{(g)}$,the enthalpy change is $\Delta H = 30 \ kJ/mol$ and the entropy change is $\Delta S = 105 \ J/mol \cdot K$. The temperature at equilibrium is $...... \ K$.

One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27\,^oC$. If the work done during the process is $3\,kJ$,the final temperature will be equal to $(C_v = 20\,J\,K^{-1} \, mol^{-1})$

$A$ $10 \ g$ piece of iron $(C = 0.45 \ J/g \ ^oC)$ at $100 \ ^oC$ is dropped into $25 \ g$ of water $(C = 4.2 \ J/g \ ^oC)$ at $27 \ ^oC$. Find the temperature of the iron and water system at thermal equilibrium in $^oC$.

$CsOH + HCl \to CsCl + H_2O$,$\Delta H = -13.4 \ K \ cal/mol$
$CsOH + HA \to CsA + H_2O$,$\Delta H = -10.4 \ K \ cal/mol$
Then calculate $\Delta H$ of ionisation of $HA$ in $K \ cal/mol$.