Hello! 1. The problem statement, all variables and given/known data Please, take a look at the problem and at my solution. Have I done it correctly and is my logic correct? How much of a 10 liter 30% acid solution must be replaced with pure acid to obtain 10 liters of a 50% solution? 2. Relevant equations 3. The attempt at a solution I need to get 10 liters of final solution that contains 5 liters of acid. Let X be the volume of 30% solution, and Y the volume of pure acid. Than: X + Y = 10 0.3 X + Y = 5 I take 0.3X of 30% solution and add Y of acid to get 5 liters of acid. Y = 2.857 Thank you!