The heat of solution of anhydrous $$\mathrm{CuSO}_4$$ and $$\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$$ are $$-70 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ and $$+12 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ respectively.
The heat of hydration of $$\mathrm{CuSO}_4$$ to $$\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$$ is $$-x \mathrm{~kJ}$$. The value of $$x$$ is ________. (nearest integer).
$$\Delta_{\text {vap }} \mathrm{H}^{\ominus}$$ for water is $$+40.79 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ at 1 bar and $$100^{\circ} \mathrm{C}$$. Change in internal energy for this vapourisation under same condition is ________ $$\mathrm{kJ} \mathrm{~mol}^{-1}$$. (Integer answer) (Given $$\mathrm{R}=8.3 \mathrm{~JK}^{-1} \mathrm{~mol}^{-1}$$)
Consider the figure provided.
$$1 \mathrm{~mol}$$ of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at $$18^{\circ} \mathrm{C}$$. If the piston is moved to position $$\mathrm{B}$$, keeping the temperature unchanged, then '$$\mathrm{x}$$' $$\mathrm{L}$$ atm work is done in this reversible process.
$$\mathrm{x}=$$ ________ $$\mathrm{L}$$ atm. (nearest integer)
[Given : Absolute temperature $$={ }^{\circ} \mathrm{C}+273.15, \mathrm{R}=0.08206 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}{ }^{-1} \mathrm{~K}^{-1}$$]
For the reaction at $$298 \mathrm{~K}, 2 \mathrm{~A}+\mathrm{B} \rightarrow \mathrm{C}, \Delta \mathrm{H}=400 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ and $$\Delta S=0.2 \mathrm{~kJ} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$. The reaction will become spontaneous above __________ $$\mathrm{K}$$.