It can also be confusing if you check the volumes after mixing, since the water-alcohol interaction decreases the molecular spacing and the total volume. V_(wa

It can also be confusing if you check the volumes after mixing, since the water-alcohol interaction decreases the molecular spacing and the total volume. V_(water + alcohol) < V_water + V_alcohol. https://en.wikipedia.org/wiki/Alcohol_by_volume#Volume_change https://en.wikipedia.org/wiki/Alcohol_by_volume#Volume_chang...