# What is the concentration in m/m% of a solution prepared from 50.0 g NaCl and 150.0 g of water?

Jun 7, 2017

25.0%

#### Explanation:

A solution's mass by mass percent concentration, $\text{m/m%}$, tells you the number of grams of solute present for every $\text{100 g}$ of solution.

Your solution contains two substances: sodium chloride, $\text{NaCl}$, the solute, and water, the solvent. To find the total mass of the solution, add the mass of the solute and the mass of the solvent.

$\text{mass solution = 50.0 g + 150.0 g}$

$\text{mass solution = 200.0 g}$

Now, this solution contains $\text{50.0 g}$ of solute in

$\text{200.0 g" = color(red)(2) * "100.0 g}$

of solution. This means that $\text{100.0 g}$ of solution will contain

$\text{50.0 g"/color(red)(2) = "25.0 g}$

of solute. Since this represents the amount of solute present in $\text{100.0 g}$ of solution, you can say that the mass by mass percent concentration is equal to

$\textcolor{\mathrm{da} r k g r e e n}{\underline{\textcolor{b l a c k}{\text{m/m% = 25.0% NaCl}}}}$

The answer is rounded to three sig figs.