What is the mass of the solute in $g$ in $1 \ L$ of a solution having $40\%$ concentration by weight? The density of the solution is $1.2 \ g/mL$.

The concentration of $Ca^{2+}$ ions in a water sample is $0.0002 \ M$. What is the concentration of $Ca^{2+}$ in $ppm$ by weight-volume?

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 $CHCl_3 = 1.49 \ g \ cm^{-3}$.

Explain $\% \ V/V$ in brief.

What is the mole fraction of water in $10\%$ by weight $(w/w)$ of aqueous urea solution? [Given: Molar mass of $H, O, C$ and $N$ are $1, 16, 12$ and $14 \text{ g mol}^{-1}$ respectively.]

When $1.04 \ g$ of $BaCl_2$ is dissolved in $10^5 \ g$ of water,what will be the concentration of the solution in $ppm$?