If $15 \ g$ of $NaOH$ is dissolved in water to make $250 \ mL$ of solution,find the molarity of this solution in $M$.

$1 \ g$ of a solute is added to $18 \ g$ of water. In this aqueous solution,what is the mass per cent of the solute (in $\%$)?

Some amount of dichloromethane $(CH_2Cl_2)$ is added to $671.141 \ mL$ of chloroform $(CHCl_3)$ to prepare a $2.6 \times 10^{-3} \ M$ solution of $CH_2Cl_2$ $(DCM)$. The concentration of $DCM$ is $......... \ ppm$ (by mass). Given: Atomic mass: $C = 12, H = 1, Cl = 35.5$; density of $CHCl_3 = 1.49 \ g \ cm^{-3}$.

Calculate the concentration of fluorine in $ppm$ in $500 \ g$ of toothpaste containing $0.2 \ g$ of fluorine.

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.

Which of the following modes of expressing concentration is independent of temperature?