We are being asked to calculate the amount of water (in grams) that must be added to 26.2 g of MgCl_{2} in the preparation of a 15.0 percent of MgCl_{2} solution by mass.

**Mass** or **weight percent (% by mass) **is the percentage of a given element or compound within a solution.

The equation used to calculate the mass percent is shown below:

$\overline{){\mathbf{m}}{\mathbf{a}}{\mathbf{s}}{\mathbf{s}}{\mathbf{}}{\mathbf{p}}{\mathbf{e}}{\mathbf{r}}{\mathbf{c}}{\mathbf{e}}{\mathbf{n}}{\mathbf{t}}{\mathbf{}}{\mathbf{=}}{\mathbf{}}\frac{\mathbf{m}\mathbf{a}\mathbf{s}\mathbf{s}\mathbf{}\mathbf{c}\mathbf{o}\mathbf{m}\mathbf{p}\mathbf{o}\mathbf{n}\mathbf{e}\mathbf{n}\mathbf{t}}{\mathbf{t}\mathbf{o}\mathbf{t}\mathbf{a}\mathbf{l}\mathbf{}\mathbf{m}\mathbf{a}\mathbf{s}\mathbf{s}}{\mathbf{\times}}{\mathbf{100}}}$

**The solution was prepared by dissolving ****26.2 g of MgCl _{2} in **

Calculate the amount of water (in grams) that must be added to 26.2 g of MgCl_{2} in the preparation of a 15.0 percent of MgCl_{2} solution by mass.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Mass Percent concept. You can view video lessons to learn Mass Percent. Or if you need more Mass Percent practice, you can also practice Mass Percent practice problems.