A researcher dilutes 30.0 ml of ethanol to 300.0 ml with distilled water. what is the percentage concentration by volume of the resulting solution?9.09.10%

Percent by volume is calculated by dividing the amount of solute by the total amount of solution. Take note that the amounts here are in units volume. We need to assume that volume effects are negligible so that we can add the volumes.

Percent by volume = 30 / 300 + 30 x 100 = 9.091%