$1 \, M$ solution contains

$A$ solution is $0.25 \%$ by mass. What is the weight of solvent containing $1.25 \ g$ solute (in $g$)?

If $50 \%$ of $1 \ M \ Na_2SO_4$ is dissociated in an aqueous solution of density $1.2 \ g \ mL^{-1}$,what is the molality of $Na^{+}$ ion in the solution?

Molarity $(M)$ of an aqueous solution containing $x \ g$ of anhydrous $CuSO_4$ in $500 \ mL$ solution at $32^{\circ} C$ is $2 \times 10^{-1} \ M$. Its molality will be. . . . . .$\times 10^{-3} \ m$ (nearest integer). [Given density of the solution $= 1.25 \ g/mL$.]

The density of a $1.0 \ M$ aqueous solution of glucose is $1.1 \ g/mL$. What is the molality of the solution in $m$ (in $m$)?

If a substance $A$ dissolves in a solution of a mixture of $B$ and $C$ with their respective number of moles as $n_A, n_B$ and $n_C$,the mole fraction of $C$ in the solution is: