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 mole fraction of the solute in $2.5 \ m$ aqueous solution?

For a very diluted solution,the preferred concentration unit is:

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

The density of '$x$' $M$ solution ('$x$' molar) of $NaOH$ is $1.12 \ g \ mL^{-1}$. While in molality,the concentration of the solution is $3 \ m$ $(3 \ molal)$. Then '$x$' is.
(Given: Molar mass of $NaOH$ is $40 \ g \ mol^{-1}$)

$A$ solution is $0.25 \%$ by mass. What is the weight of solvent containing $1.25 \ g$ solute (in $g$)?