The amount of $NaOH$ in $g$ in $250\,cm^3$ of a $0.100\,M\,NaOH$ solution would be ........... $g$.

Density of a $2.05 \ M$ solution of acetic acid in water is $1.02 \ g/mL$. The molality of the solution is ............. $mol \ kg^{-1}$.

If a solution of methyl alcohol $(CH_3OH)$ is $5.2 \ m$ (molal) in water,what is the mole fraction of methyl alcohol in the solution?

The mole fraction of a solute in a $100$ molal aqueous solution is $.......... \times 10^{-2}$ (Round off to the nearest integer). [Given: Atomic masses: $H = 1.0 \ u$,$O = 16.0 \ u$]

For a solution containing $0.03659 \ g/mL$ of $HCl$ and a solution containing $0.04509 \ g/mL$ of acetic acid $(CH_3COOH)$,which of the following is true?

$A$ sample of drinking water was found to be severely contaminated with chloroform,$CHCl_{3}$,supposed to be carcinogenic in nature. The level of contamination was $15 \ ppm$ (by mass).
$(i)$ Express this in percent by mass.
$(ii)$ Determine the molality of chloroform in the water sample.