Commercial bleach contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Calculate the molarity of this solution. (Hints: assume you have 1 L of solution (mass 1080 g); molar mass of NaClO is 74.4 g/mol)

Answer 1

How much does a L weight?
1000 mL x 1.08 g/mL = 1080 grams.
How much of that is NaClO?
1080 g x 0.0525 = ?? grams NaClO.
How many moles NaClO is that?
??grams NaClO/molar mass NaClO = moles NaClO and that is in 1 L of solution so that is the molarity.