# Percetnage by volume of propanol from original volumes

1. ### lavster

217
if i had 500ml of water and added 250ml of propanol, how would I go about working out its percentage by volume???

thanks

2. ### sjb-2812

439
What is the total volume?

3. ### Yanick

401
It depends on what level of accuracy you need to work in. For many applications simply adding the volumes will yield an acceptable answer. However, volumes are not necessarily additive, and very precise work would use the partial molar volumes to determine such things.

For further reading: Partial Molar Property on Wikipedia