Question

How much water should be added to a 15 gallon solution of 35% hydrogen peroxide to create an 8% solution? how many gallons would there be of the 8% solution?

Answer 1

15 gallons of 35% peroxide solution contains 0.35 × 15 = 5.25 gallons of hydrogen peroxide. The rest of the volume is made up of 15 - 5.25 = 9.75 gallons of water.

If we add
`x` gallons of water to the solution, the amount of hyrdrogen peroxide in the solution stays the same, but the volume of water increases to
`9.75+x` gallons, and the total volume increases to
`15+x` gallons.

To get a concentration of 8% in this diluted solution, we add
`x` gallons of water such that

`(5.25)/(15+x) = 0.08`

Solve for
`x`.

`5.25 = 0.08 (15 + x)`

`5.25 = 1.2 + 0.08x`

`0.08x = 4.05`

`x = 50.625`

To get the desired concentration, one must add 50.625 gallons of water, and one will end up with a total volume of 65.625 gallons of solution.