Pure acid is to be added to a 5 acid solution to obtain 95 L

Pure acid is to be added to a 5% acid solution to obtain 95 L of 26% solution. What amounts of each should be used? Amount of 100%

Amount of 5%

Solution

Let x liters of pure (100% acid be added to y liters of 5 % acid solution to get 95 liters of 26 % acid solution. Then x + y = 95 so that y = 95 –x. Also x + (95 –x)* 5/100 = 95*26/100 or, x + (95-x)/20 = 2470/100 or, x – x/20 = 247/10 – 95/20 or, 19x/20 = 399/20 or, 19x = 399 so that x = 21. Then y = 95 - x = 95 - 21 = 74.Thus 21 liters of pure(100%) acid has to be added to 74 liters of 5 % acid solution to get 95 liters of 26 % acid solution.