$1 \, \text{mole}$ of $H_2SO_4$ is mixed with $2 \, \text{moles}$ of $NaOH$. The heat evolved will be

Find the enthalpy of neutralisation in $kJ/mol$ for the reaction between $NH_4OH$ and $HCN$ in aqueous solution,given that the enthalpies of ionisation of $NH_4OH$ and $HCN$ are $7 \ kJ/mol$ and $8 \ kJ/mol$ respectively,and the enthalpy of neutralisation of a strong acid and a strong base is $-57.3 \ kJ/mol$.

$A$ fish swimming in a water body,when taken out,is covered with a film of water of weight $36 \ g$. When it is subjected to cooking at $100^{\circ} C$,the internal energy change for vaporization in $kJ \ mol^{-1}$ is $......$ [nearest integer].
[Assume steam to be an ideal gas. Given $\Delta_{vap} H^{\ominus}$ for water at $373 \ K$ and $1 \ bar$ is $41.1 \ kJ \ mol^{-1}$; $R = 8.31 \ J \ K^{-1} \ mol^{-1}$]

For irreversible expansion of an ideal gas under isothermal condition,the correct option is :

$A$ solution of $500 \ mL$ of $2 \ M \ KOH$ is added to $500 \ mL$ of $2 \ M \ HCl$ and the mixture is well shaken. The rise in temperature $T_1$ is noted. The experiment is then repeated using $250 \ mL$ of each solution and the rise in temperature $T_2$ is again noted. Assume all heat is absorbed by the solution.

The heat of vaporisation and heat of fusion of $H_2O$ are $540 \, cal/g$ and $80 \, cal/g$. The ratio of $\frac{\Delta S_{vap}}{\Delta S_{fusion}}$ for water is :-