Question

Molly has 20ml of a 20% sulfuric acid solution and she is mixing it with a 5% sulfuric acid solution. How many millimeters of 5% sulfuric solution must she add in order to end up with a 12% sulfuric acid solution. Round answer to nearest millimeter.

Answer 1

Molly has to add 22.86 milliliters of 5% sulfuric acid.

Explanation:

Molly has a mixture of 20 ml of 20% sulfuric acid solution.

She mixes this with 5% sulfuric acid solution and in the end she wants a 12% sulfuric acid solution.

We have to find how many milliliters of 5% sulfuric acid we have to add to make it 12% solution.

Let the volume we add be v milliliters.

We are going to equate sulfuric acid.

`20* 0.2 + v* 0.05 = (20+v)* 0.12`

v =
`(160)/(7)` milliliters

v = 22.86 milliliters