SOLUTION: I want to make 200 LIters of a 5% acid solution. If I have a 25% acid solution, how much water and how much of the 25% acid solution should I use?

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Question 708332: I want to make 200 LIters of a 5% acid solution. If I have a 25% acid solution, how much water and how much of the 25% acid solution should I use?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
EDIT: Added explanation after the end.

Water with "nothing else" in it will have 0% acid. You have 25% acid and you want to add water, of 0% acid to make 5% acid.

How much acid will be?
How much volume of mixture will result?
What concentration of acid must result?
----------> Rational Equation:

Let x be how much water
Let y be how much 25% acid

%280%2Ax%2B25%2Ay%29%2F200=5
AND
x%2By=200

Solve for y in the rational equation. Use that result in the volume sum equation to find x.

FURTHER EXPLANATION: The reason I said that last part is because 0%2Ax=0 in the rational equation. This means the rational equation only has one variable, the y. One single linear y, easy to solve. Then use the volume sum equation to find x.