# Question 863ff

Apr 5, 2016

$\text{12.0 g NaCl}$

#### Explanation:

The problem provides you with the solution's percent concentration by mass, which essentially tells you how much solute you for every $\text{100 g}$ of solution.

In this case, a "12.0% sodium chloride solution will contain $\text{12.0 g}$ of sodium chloride, which is your solute, for every $\text{100. g}$ of solution.

That is to say that you can make this solution by dissolving $\text{12.0 g}$ of sodium chloride in $\text{88.0 g}$ of water. The total mass of the solution will be

${m}_{\text{solution" = overbrace("12.0 g")^(color(red)("solute")) + overbrace("88.0 g")^(color(blue)("solvent")) = "100. g}}$

Since the solution contains $\text{12.0 g}$ of sodium chloride in $\text{100. g}$ of water, its percent concentration by mass will be 12.0%#.