Standard enthalpy of vapourisation for $$\mathrm{CCl}_4$$ is $$30.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$$. Heat required for vapourisation of $$284 \mathrm{~g}$$ of $$\mathrm{CCl}_4$$ at constant temperature is ________ $$\mathrm{kJ}$$.

(Given molar mass in $$\mathrm{g} \mathrm{mol}^{-1} ; \mathrm{C}=12, \mathrm{Cl}=35.5$$)

If $$50 \mathrm{~mL}$$ of $$0.5 \mathrm{M}$$ oxalic acid is required to neutralise $$25 \mathrm{~mL}$$ of $$\mathrm{NaOH}$$ solution, the amount of $$\mathrm{NaOH}$$ in $$50 \mathrm{~mL}$$ of given $$\mathrm{NaOH}$$ solution is ______ g.

The following concentrations were observed at $$500 \mathrm{~K}$$ for the formation of $$\mathrm{NH}_3$$ from $$\mathrm{N}_2$$ and $$\mathrm{H}_2$$. At equilibrium ; $$\left[\mathrm{N}_2\right]=2 \times 10^{-2} \mathrm{M},\left[\mathrm{H}_2\right]=3 \times 10^{-2} \mathrm{M}$$ and $$\left[\mathrm{NH}_3\right]=1.5 \times 10^{-2} \mathrm{M}$$. Equilibrium constant for the reaction is ________.

A constant current was passed through a solution of $$\mathrm{AuCl}_4^{-}$$ ion between gold electrodes. After a period of 10.0 minutes, the increase in mass of cathode was $$1.314 \mathrm{~g}$$. The total charge passed through the solution is _______ $$\times 10^{-2} \mathrm{~F}$$.

(Given atomic mass of $$\mathrm{Au}=197$$)