The density of a stock solution of $29.2\% \, (w/w) \, HCl$ is $1.25 \, g \, mL^{-1}$. If the molar mass of $HCl$ is $36.5 \, g \, mol^{-1}$,what volume (in $mL$) of the stock solution is required to prepare $200 \, mL$ of $0.4 \, M \, HCl$ solution?

Calculate the molarity of $NaOH$ solution prepared by dissolving $0.4 \ g$ of $NaOH$ in enough water to form $500 \ mL$ of the solution. (in $M$)

$A$ 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.

The normality of a solution of sodium hydroxide,$100 \ mL$ of which contains $4 \ g$ of $NaOH$,is:

Calculate the mass fraction and mass percentage of aspirin in a solution prepared by dissolving $3.65 \, g$ of aspirin in $25.08 \, g$ of water.

What is the molarity of a solution of $HCl$ which contains $49\%$ by weight of solute and whose specific gravity is $1.41$ (in $M$)?