Question

A chemist needs 70 milliliter of 29% solution but has only 19% and 33% solutions available. Find how many milliliter of each that should be mixed to get the desired solution

Answer 1

• 50 mL of 33%
• 20 mL of 19%

Explanation:

Let x represent the volume in mL of 33% solution needed. Then 70-x is the volume of 19% solution required. The total amount of solute is ...

0.33x + 0.19(70 -x) = 0.29(70)

0.14x = 70(0.29 -0.19)

x = 70(0.10/0.14) = 50

50 mL of 33% solution should be mixed with 20 mL of 19% solution to get the desired mix.