How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the remaining solution contains 16% peroxide?

Lets say you add x liters of peroxide

then the total number of liters will be 12+x

presently you have 8% of 12 or. 96 liters of peroxide

when you add x liters you will have. 96+x liters of peroxide total

you want that to be 16% of (12+x) so set

.96+x=.16 (12+x)

solve for x

multiply both sides by 100

96 + 100x = 16 (12+x)

96 + 100x = 192 + 16x

84x = 96

x = 1.19

So 1.19 liters

The question above may be solved using the overall mass and component balances. If we let x be the number of liters of peroxide that should be added, the final mixture will have a quantity of x+12 L. The peroxide balance before and after mixing is,

x (1) + 12 (0.08) = (x + 12) (0.16)

The value of x is 1.143. Thus, approximately 1.143 L of peroxide should be added to the original solution.