Convert 60 percent solution to 40 percent solution? - Answers

All percentages are in mass% and all quantities are in grams (mass), be sure do not to take volumes into account because mass is 'additive', volumes are not quantitatively additable!Answer: Take whatever mass of 60 percent solution you have, multiply that mass by 20 (=60-40) and then divide that amount by 40, this is how much water to add to get an 40% solution.Example: Suppose you have 100 gram of 60% solution, then you should add:100 * (60-40)/40 = 100*0.50 = 50 gram of water; this is to be added to 100 gram of 60% solution to get (50 + 100 =) 150 gram of 40% solution.(see on top of the page to know why this calculation method is not valid for 'volumes')