How much pure water must be mixed with 10 liters of a 25% acid solution to reduce it to a 10% acid solution?

1 Answer
May 30, 2017

15 litres of added water

Explanation:

We need to reduce 25% to 10%

Let the amount of acid in the mix be #x/100#

This gives a final acid content of #x/100xx25%#

The target concentration is 10%

Set #x/100xx25%=10%#

#x=(10%xx100)/(25%)#

#x=40#

Thus #40/100# of the final blend is the acid
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Let the total volume of the blend be #v#

We have 10 litres of acid so

#40/100v=10#

#v=(10xx100)/40 =100/4=25# litres all together

Thus the added water is 25-10=15 litres