Calculate the mass percentage of $3 \ g$ of solute $A$ dissolved in $18 \ g$ of water. (in $\%$)

Calculate the molarity of a solution containing $5 \, g$ of $NaOH$ in $450 \, mL$ solution. (in $, M$)

What is the mole fraction of the solute in a $2.5 \, m$ aqueous solution?

The molarity of the solution obtained by mixing $750 \ mL$ of $0.5 \ (N) \ HCl$ with $250 \ mL$ of $2 \ (M) \ HCl$ is ........... $M$.

$3.0\, g$ of oxalic acid $[(CO_2H)_2 \cdot 2H_2O]$ is dissolved in a solvent to prepare a $250\, mL$ solution. The density of the solution is $1.9\, g/mL$. The molality and normality of the solution,respectively,are closest to

Molarity of a solution prepared by dissolving $75.5 \ g$ of pure $KOH$ in $540 \ mL$ solution is .......... $M$