The plot given below shows $$P-T$$ curves (where $$P$$ is the pressure and $$T$$ is the temperature) for two solvents $$X$$ and $$Y$$ and isomolal solutions of $$NaCl$$ in these solvents. $$NaCl$$ completely dissociates in both the solvents.



On addition of equal number of moles of a non-volatile solute $$S$$ in equal amount (in $$kg$$) of these solvents, the elevation of boiling point of solvent $$X$$ is three times that of solvent $$Y$$. Solute $$S$$ is known to undergo dimerization in these solvents. If the degree of dimerization is $$0.7$$ in solvent $$Y$$, the degree of dimerization in solvent $$X$$ is ___________.

The mole fraction of a solute in a solution is 0.1. At 298 K, molarity of this solution is the same as its molality. Density of this solution at 298 K is 2.0 g cm^–3 . The ratio of the molecular weights of the solute and solvent, $$\left( {{{M{W_{solute}}} \over {M{W_{solvent}}}}} \right)$$, is

If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex(which behaves as a strong electrolyte) is – 0.0558^oC, the number of chloride(s) in the coordination sphere of the complex is [K_f of water = 1.86 K kg mol^–1 ]

MX₂ dissociates in M²⁺ and X^- ions in an aqueous solution, with a degree of dissociation ($$\alpha$$) of 0.5. The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in the absence of ionic dissociation is