Hi,
Can you explain to me how mixing a solution with 20% hydrogen peroxide with another solution that contains .05% hydrogen peroxide and not adding any water yields 15% hydrogen peroxide?

Note that understand the math formula provided in the solution. However I don't see how not diluting any mixture will yield less hydrogen peroxide.

Thanks in advance for your help with this.

Mary Kay Richardson

Here is how we set this problem up

We begin with 3 quarts of Minum. Since Minum is 5% HP by volume, then (5/100)(3 Qt) = 0.15 Qt HP in the Minum.

Next we have some volume, say x, of Maxim. And, Maxim is 20% HP, so (20/100)(x Qt) = 0.2x Qt HP in the Maxim.

The question asks how much of Maxim we have to add to Minum to end up with a solution that is 15% HP:

So we take the part over the whole and set it equal to the percentage:

Volume of solution that is HP / Total Volume = 15/100

[ (0.15) + (0.2)x ] / [3 + x ] = 15/100 We simply cross multiply here and solve for x. x = 6