Question

A pharmacist wants to make 20 ml of a 59% hydrogen peroxide solution. How many mls of 35% hydrogen peroxide must he mix with 75% hydrogen peroxide to make the desired solution?

Answer 1

@superhelp101

Answer 2

the pharmacist needs how many of 35%???

Answer 3

and 75%???

Answer 4

@AntonioCochrane

Answer 5

@Cosmichaotic

Answer 6

@FriedRice

Answer 7

@aum

Answer 8

Let the mixture be made from "x" ml of 35% hydrogen peroxide and
(20-x) ml of 75% hydrogen peroxide.

x ml of 35% hydrogen peroxide will have 0.35x of hydrogen peroxide.
(20-x) ml of 75% hydrogen peroxide will have 0.75(20-x) of hydrogen peroxide.

Total hydrogen peroxide = 0.35x + 0.75(20-x) =
0.35x + 15 - 0.75x = 15 - 0.4x

The mixture has (15 - 0.4x) ml of hydrogen peroxide in 20 ml of solution.
The concentration of the mixture is 59%.

Therefore, 15 - 0.4x = 20 * .59 = 11.8
15 - 11.8 = 0.4x
0.4x = 3.2
x = 8

So the pharmacist should mix 8 ml of 35% hydrogen peroxide with 12 ml of 75% hydrogen peroxide to get the 20 ml of a 59% hydrogen peroxide solution.