Answer:
13.3 %
Explanation:
Percent by mass indicates the mass of solute in 100g of solution.
We must know the solution's mass:
Solution's mass = Solute mass + solvent mass
Solution's mass = 10 g + 65 g = 75 g
Percent by mass = (10 g / 75 g).100 = 13.3 %
Otherwise, we can make a rule of three:
In 75 g of solution we have 10 g of solute
In 100 g of solution we must have (100 . 10) /75 = 13.3 %
