Question

A chemist has a solution that is 20% hydrochloric acid (hcl) and a solution that is 50% hcl. how much of each solution should be mixed to obtain 300 cubic centimeters (cc) of a solution that is 30% hcl?

Answer 1

Please examine explanation

Explanation:

First acid (20%), amount V (which is volume (in cc))
Second acid (50%), amount `300-V`

Now compute the amounts (volumes)

`0.30times300 = 0.20timesV + 0.50times(300-V)`

`90 = 0.2V + 150 - 0.5V`
`90-150 = -0.3V`
`-60=-0.3V`

`V=200` cc (from 20% HCl)

The rest (100 cc) should be taken from 50% HCl solution.

Your answer is 200 cc from 20% HCl and 100 cc from 50% HCl solution will do.