Answer to Question #244170 in Inorganic Chemistry for Awit

Question

How much salt and how much water must be mixed to make 250 g brine solution that is 50% salt by mass?

Answer 1

The key is to recognize the percentage concentration is mass of solute divided by mass of solution, not the original solvent.

If you add x grams of salt, the solution has a mass of 250 g + x

x/(250 g + x) = 0.5

x = 250 g × 0.5/0.5 = 250g (rounded)