An experiment requires a solution of 60 % ethanol by volume. What volume of alcohol should be added to make a 200 mL of this solution?​

120 mL of ethanol must be added.

Explanation:

We are given:

60% ethanol by volume

This means that 60 mL of ethanol is present in 100 mL of solution

Given volume of solution = 200 mL

Applying unitary method:

If 100 mL of solution contains 60 mL of ethanol

So, 200 mL of solution will contain = of ethanol

Hence, 120 mL of ethanol must be added.