Question

A solution of NaCl has a concentration of 1.50 M. The density of the solution is 1.06 g/mL. What is the concentration solution by percent in mass?

Answer 1

8.27% on edge

Step-by-step explanation:

Answer 2

The concentration solution by percent in mass is 8.28%

Step-by-step explanation:

Molarity is moles of solute present in 1L of its solution .

Hence the formula is

`$\left.\text {Molarity}=\frac{\text {moles of solute}}{\text {Volume of solution in } L} \text { (unit is } \frac{\text { mol }}{L} \text { or } M\right)=\frac{1.50 \mathrm{mol}}{1 \mathrm{L}}$`

Let us convert the numerator and the denominator into mass in g

Numerator :

`mass $=$ moles $*$ molar mass\\\\$=1.50 \mathrm{mol} * 58.5 \frac{g}{\text { mol }}=87.75 \mathrm{g}$ (solute)`

Denominator :

`$\begin{aligned} \text {mass} &=\text { density } * \text {volume}=\frac{1.06 \mathrm{g}}{1 \mathrm{ml}} * 1 \mathrm{L} \\\\ &=\frac{1.06 \mathrm{g}}{1 \mathrm{ml}} * 1000 \mathrm{ml}=1060 \mathrm{g} \end{aligned}$`

The formula to find mass percentage is

`$\%$ mass $=\frac{\text { mass of solute }}{\text { mass of solution }} * 100 \%$`

`$\%$ mass of $\mathrm{NaCl}=\frac{\text { mass of solute }}{\text { mass of solution }} * 100 \%$`

`$=(87.75 g)/(1060 g) * 100 \%$\\`

=8.28% (Answer)