An aqueous solution of an unknown solute " $X$ " is prepared by adding 4.0 g of it into 2.0 moles of water. What is the mass percent of " $X$ " in the aqueous solution?

What is the percentage dissociation of 0.8 ml of Acetic acid (density is $1.04 \mathrm{~g} / \mathrm{ml}$ ) which is dissolved in 1.2 L of water if the observed Depression in freezing point is 0.0228 K ? ( $\mathrm{K}_{\mathrm{f}}$ for water $=1.86 \mathrm{Kkg} / \mathrm{mol}$.)

Identify the correct statement

0.02 M solution of sucrose is isotonic with 0.008 M solution of sodium sulphate. What is the percentage dissociation of the electrolyte?