Which among the following is a unitless physical quantity?

The density of $NH_4OH$ solution is found to be $0.6 \, g/mL$. It contains $35 \%$ by mass of $NH_4OH$. The normality of the solution is ......... $N$.

$100 \ g$ of solute is dissolved in $1400 \ g$ of solvent. The density of the resultant solution is $1.5 \ g/mL$. The ratio of its molarity $(M)$ to molality $(m)$ is:

Calculate the molarity of $NaOH$ in the solution prepared by dissolving $4 \,g$ of it in enough water to form $250 \,mL$ of the solution. (in $,M$)

Which of the following is incorrect for the mole fraction $(x)$?

$A$ solution of $Al_2(SO_4)_3$ $(d = 1.253 \ g/mL)$ contains $22\%$ salt by weight. The molarity,normality,and molality of the solution are: