In Carius tube, an organic compound '$$\mathrm{X}$$' is treated with sodium peroxide to form a mineral acid 'Y'.

The solution of $$\mathrm{BaCl}_{2}$$ is added to '$$\mathrm{Y}$$' to form a precipitate 'Z'. 'Z' is used for the quantitative estimation of an extra element. '$$\mathrm{X}$$' could be

Match List I with List II

Choose the correct answer from the options given below:

An aqueous solution of volume $$300 \mathrm{~cm}^{3}$$ contains $$0.63 \mathrm{~g}$$ of protein. The osmotic pressure of the solution at $$300 \mathrm{~K}$$ is 1.29 mbar. The molar mass of the protein is ___________ $$\mathrm{g} ~\mathrm{mol}^{-1}$$

Given : R = 0.083 L bar K$$^{-1}$$ mol$$^{-1}$$

The number of molecules from the following which contain only two lone pair of electrons is ________

$$\mathrm{H}_{2} \mathrm{O}, \mathrm{N}_{2}, \mathrm{CO}, \mathrm{XeF}_{4}, \mathrm{NH}_{3}, \mathrm{NO}, \mathrm{CO}_{2}, \mathrm{~F}_{2}$$