Chapter 7, Problem 7.32E

Calculate the concentration in $\%\left(\text{w}/\text{w}\right)$ of the following solutions:

a. $20.0\text{g}$ of solute is dissolved in enough water to give $150.\text{mL}$ of solution. The density of the resulting solution is $1.20\text{g}/\text{mL}$.

b. A $\text{10}\text{.0-mL}$ sample with a density of $1.10\text{g}/\text{mL}$ leaves $1.18\text{g}$ of solid residue when evaporated.

c. A $\text{25}\text{.0}\text{-g}$ sample of solution on evaporation leaves a $\text{1}\text{.87-g}$ residue of ${\text{MgCl}}_{\text{2}}$.