What volume of concentrated HCl, 37.2% by mass with density 1.19 g/mL, contains 125 g of HCl?

1. Work the previous route backwards, from solute mass to solution mass to volume. 2. The solution mass follows from the percentage: 125 g x 100 g solution per 37.2 g HCl. 3. That gives 336 g of solution. 4. Now use the density to convert mass into volume: 336 g / 1.19 g/mL. 5. The volume is 282 mL of concentrated solution. 6. Units cancel correctly, since grams divided by grams per millilitre leaves millilitres. 7. The value 336 mL stops at the solution mass and never divides by the density. 8. The value 105 mL multiplies by the percentage instead of dividing by it. _Source: OpenStax Chemistry (CC BY 4.0), Ch 3 "Composition of Substances and Solutions", section 3.4 Other Units for Solution Concentrations_