A solution is prepared by adding $2 \mathrm{g}$ of $\text{'}\text{'}\mathrm{X}\text{'}\text{'}$ to $1$ mole of water. Mass percent of $\text{'}\text{'}\mathrm{X}\text{'}\text{'}$in solution is 

To calculate the mass percent of ''X'' in the solution, we need to determine the mass of ''X'' and the total mass of the solution.

Given:

:Solute ($\mathrm{X}$) = $2 \mathrm{g}$

Solvent (${\mathrm{H}}_2\mathrm{O}$)$= 1 \mathrm{mole} = 18 \mathrm{g}$

Total mass $= 2 + 18 = 20 \mathrm{g}$

 Mass percent of $\mathrm{X}=\frac{2}{2+18}\times 100=10$