A sample of $$\mathrm{CaCO}_3$$ and $$\mathrm{MgCO}_3$$ weighed $$2.21 \mathrm{~g}$$ is ignited to constant weight of $$1.152 \mathrm{~g}$$. The composition of mixture is :

(Given molar mass in $$\mathrm{g} \mathrm{~mol}^{-1} \mathrm{CaCO}_3: 100, \mathrm{MgCO}_3: 84$$)

If a substance '$$A$$' dissolves in solution of a mixture of '$$B$$' and '$$C$$' with their respective number of moles as $$\mathrm{n}_{\mathrm{A}}, \mathrm{n}_{\mathrm{B}}$$ and $$\mathrm{n}_{\mathrm{C}_3}$$. Mole fraction of $$\mathrm{C}$$ in the solution is

The quantity which changes with temperature is :

A metal chloride contains $$55.0 \%$$ of chlorine by weight . $$100 \mathrm{~mL}$$ vapours of the metal chloride at STP weigh $$0.57 \mathrm{~g}$$. The molecular formula of the metal chloride is

(Given: Atomic mass of chlorine is $$35.5 \mathrm{u}$$)