# Volume/volume units question

I'm looking through articles for a presentation in college and I ran across the units volume/volume. (V/V)
From what I understand v/v is calculated with the formula (vol. solute/total volume). One of the articles has figures with over 100 v/v. How is this possible? Shouldn't it be between 0 and 1 or 0% and 100%

Borek
Mentor
Volume is not additive. If you mix 50 mL of water with 50 mL of ethanol you'll get 96.4 mL of solution.

Volume is not additive. If you mix 50 mL of water with 50 mL of ethanol you'll get 96.4 mL of solution.
Why does this happen? I can see how it would work if the two substances were at different temperatures initially but can't think of anything else that would cause it.

Borek
Mentor
Imagine adding sand to marbles, with sand filling gaps between marbles. Is the final volume sum of volumes?

That's not the only way it happens, but it will give you an example.

Imagine adding sand to marbles, with sand filling gaps between marbles. Is the final volume sum of volumes?

That's not the only way it happens, but it will give you an example.
That's a good analogy. It was talking about gas adsorbing to charcoal. I didn't take into account the nooks and crannies in charcoal that give it 'internal volume' for lack of a better word

mjc123