SOLUTION: how much pure acid must be added to 25 ounces of a solution of acid and water that is 20% pure acid in order to make a solution that is 50 % pure acid ?

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Question 429938: how much pure acid must be added to 25 ounces of a solution of acid and water that is 20% pure acid in order to make a solution that is 50 % pure acid ?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Let x represent how much pure acid needs to added to the 20% solution

Question states***

"make a solution that is 50 % pure acid" 

 1.0x + .20*25oz = .50(25oz+x)

        .5x = .30*25oz

          x = 15 oz pure acid needs to added to the 20% solution



CHECKING our Answer***

 1.0*15oz + .20*25oz = 15oz + 5oz = .5*40 = 20oz (pure acid)