Question 495618
How many liters of pure water should be mixed with a 13-L solution of 90% acid to produce a mixture that is 70% water?
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70% water = 30% acid
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13 liters of 90% acid has 12*0.9 = 11.7 liters of acid
If 11.7 l is 30%, then the total solution = 11.7/0.3 = 39 liters
39 - 13 = 26 liters of water to add