80 mole percent of $$\mathrm{MgCl}_{2}$$ is dissociated in aqueous solution. The vapour pressure of $$1.0 ~\mathrm{molal}$$ aqueous solution of $$\mathrm{MgCl}_{2}$$ at $$38^{\circ} \mathrm{C}$$ is ____________ $$\mathrm{mm} ~\mathrm{Hg.} ~\mathrm{(Nearest} ~\mathrm{integer)}$$

Given : Vapour pressure of water at $$38^{\circ} \mathrm{C}$$ is $$50 \mathrm{~mm} ~\mathrm{Hg}$$

Values of work function (W$$_0$$) for a few metals are given below

The number of metals which will show photoelectric effect when light of wavelength $$400 \mathrm{~nm}$$ falls on it is ___________

Given: $$\mathrm{h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}$$

$$c=3 \times 10^{8} \mathrm{~ms}^{-1}$$

$$e=1.6 \times 10^{-19} \mathrm{C}$$

Three organic compounds A, B and $$\mathrm{C}$$ were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The $$\mathrm{R}_{\mathrm{f}}$$ value of the most polar compound is ____________ $$\times 10^{-2}$$

The value of $$x$$ in compound 'D' is _________.