# Question #a69e3

##### 1 Answer

#### Explanation:

A solution's **percent concentration by mass**, **of solution**.

This means that in order to find a solution's percent concentration by mass, you must determine how many grams of solute you have in

In your case, the solution is said to contain **total mass** of

This means that

#100 color(red)(cancel(color(black)("g solution"))) * "90 g CaI"_2/(300color(red)(cancel(color(black)("g solution")))) = "30 g CaI"_2#

So, if

#"% m/m" = color(green)(|bar(ul(color(white)(a/a)"30%"color(white)(a/a)|)))#