A scientist needs 150mL of a 15% acid solution for an experiment. The lab has available a 10% solution and a 25% solution. How many milliliters of the 10% solution and how many milliliters of the 25% solution should the scientist mix to make the 15% solution?

100mL of 10% solution and 50 mL of 25% solution

Explanation:

Total volume needed = 150 mL

required concentration = 15%

Let the volume of 10% solution required = x mL

The volume of 25% solution required = 150-x

Let us equate the initial concentrations and volume to final concentrations and volume.

Volume of 10% solution X concentration + Volume of 25% solution X concentration = final concentration X final volume

x (10) + (150-x) 25 = 150X15

10x + 3750 - 25x = 2250

-15x = - 1500

x = 100

So we will take 100mL of 10% solution and 50 mL of 25% solution