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.

$A$ mixture of alcohol and water contains $54 \%$ water by mass. What is the mole fraction of ethanol?

Calculate the mass percentage of aspirin $(C_{9}H_{8}O_{4})$ in acetonitrile $(CH_{3}CN)$ when $6.5 \ g$ of $C_{9}H_{8}O_{4}$ is dissolved in $450 \ g$ of $CH_{3}CN$.

The normality of $4\% \ (w/V)$ $NaOH$ is

The molarity of the solution prepared by dissolving $6.3 \ g$ of oxalic acid $(H_{2}C_{2}O_{4} \cdot 2H_{2}O)$ in $250 \ mL$ of water in $mol \ L^{-1}$ is $x \times 10^{-2}$. The value of $x$ is ..... . (Nearest integer)
[Atomic mass : $H: 1.0, C: 12.0, O: 16.0]$

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?