# If the solubility of a solute is S, find its percentage by weight?

Feb 22, 2018

$\text{% by mass} = \frac{S}{100 + S}$

#### Explanation:

If the solubility is $S$, there are $S$ g solute in 100 g solvent.

$\text{Total mass of solution" = (S + 100)color(white)(l) "g}$

"% by mass" = "mass of solute"/"mass of solution" × 100 % = (S color(red)(cancel(color(black)("g"))))/((S+100) color(red)(cancel(color(black)("g")))) × 100 %

$\text{% by mass} = \frac{S}{100 + S}$