How many grams of $KCl$ would have to be dissolved in $60 \ g$ of $H_2O$ to give a $20 \%$ by weight solution?

$4.5 \ g$ of compound $A$ $(MW = 90)$ was used to make $250 \ mL$ of its aqueous solution. The molarity of the solution in $M$ is $x \times 10^{-1}$. The value of $x$ is ............ (Rounded off to the nearest integer)

The molality of a solution containing $15.20 \ g$ of urea (molar mass = $60 \ g \ mol^{-1}$) dissolved in $150 \ g$ of water is:

The mole fraction of glucose $(C_{6}H_{12}O_{6})$ in an aqueous binary solution is $0.1$. The mass percentage of water in it,to the nearest integer,is $....$.

Molality $(m)$ of $3 \text{ M}$ aqueous solution of $NaCl$ is:
(Given: Density of solution = $1.25 \text{ g mL}^{-1}$, Molar mass in $\text{g mol}^{-1}$: $Na = 23$, $Cl = 35.5$) (in $\text{m}$)

The number of moles of $NaOH$ in $2 \ L$ of $0.5 \ M \ NaOH$ solution is ..........