A solution is prepared by adding 2g of ' ' X '' to 1 mole of water....

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 ($X$) = $2g$

Solvent (${H}_{2}O$)$= 1mole = 18g$

Total mass $= 2 + 18 = 20g$

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