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 $$35.5 \mathrm{u}$$)

A solution is prepared by adding $$2 \mathrm{~g}$$ of "$$\mathrm{X}$$" to 1 mole of water. Mass percent of "$$\mathrm{X}$$" in the solution is :

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A : $$3.1500 \mathrm{~g}$$ of hydrated oxalic acid dissolved in water to make $$250.0 \mathrm{~mL}$$ solution will result in $$0.1 \mathrm{~M}$$ oxalic acid solution.

Reason $$\mathbf{R}$$ : Molar mass of hydrated oxalic acid is $$126 \mathrm{~g} \mathrm{~mol}^{-1}$$

In the light of the above statements, choose the correct answer from the options given below.