Mass or volume percent problem?

Question

a solution id prepared by mixing 5.0 mL ethyl alcohol in 100.0 mL water. what is the volume percent of C2H5OH in this solution?

Answer 1

approximately 100 x 5/105 = 4.76% by volume. This is an approximation because ethanol-water mixtures have less volume than the sum of their individual components. The volume percent in the final solution will accordingly be somewhat greater than 4.76%.