# %Mass of Two Phase Solvent System

## Recommended Posts

I'm hoping for some help in figuring out this problem as it is a bit beyond my scope as a Microbiologist.

I'm working with solvent systems and have a system that is    4.8 : 0.2 : 4 : 1  (Heptane. Ethyl Acetate: Ethanol : H20)

I'm trying to figure out the percentage mass of each constituent within the solvent systems lower phase.....  so it would constitute mainly the Ethyl Acetate/Ethanol/H20

Any help/ guidance would be greatly appreciated.

##### Share on other sites

The first thing is to confirm what thos numbers refer to

are they volumes, masses or molar fractions or what?

The second is more relevant to some of these possibilities than others

What is the temperature?

##### Share on other sites

ambient temp.

And those numbers relate to volume....   4.8L : 0.2L  etc etc

##### Share on other sites
2 hours ago, RyanT said:

I'm hoping for some help in figuring out this problem as it is a bit beyond my scope as a Microbiologist.

I'm working with solvent systems and have a system that is    4.8 : 0.2 : 4 : 1  (Heptane. Ethyl Acetate: Ethanol : H20)

I'm trying to figure out the percentage mass of each constituent within the solvent systems lower phase.....  so it would constitute mainly the Ethyl Acetate/Ethanol/H20

Any help/ guidance would be greatly appreciated.

It's unrealistic to try to calculate it. You would need to measure it.
About the best you can say is mainly ethanol/ water, and not much heptane.

##### Share on other sites

So there is no type of process like a ternary diagram that can be used for a biphasic system that is more than 3 constituents?

##### Share on other sites

You could, in principle, collect the data. You might even be able to "draw" it- with lots of colours on a 3D shape or something- but just think how many of them you would need.

With a dozen solvents you need to record the data for 12 things.

With pairs of solvents you have 72 to deal with.

I'm not sure, but I think you get (12^3)/3 = 573 ternary mixtures and about 5000 quaternary ones.

For each of those combinations you need to sample the behaviour at a reasonable number of points.

For a binary mixture 10 or so is probably OK, (0% a,10%a, 20%a 30%a...and so on up to 100%a) for a ternary one I think you need something like 100 points on the surface to get a good indication of what happens.

For ternary mixtures you need to consider 1000 and for quaternary ones it takes about 10,000 points to sample the search space.

So, a book listing the properties of the mixtures of 12 solvents would need something like 50,000,000 experiments.And it would need something like 5000 pages showing an incomprehensible diagram.

Good luck getting someone to do all that work.

##### Share on other sites

Haha yeah that is pretty unfeasible.

Well testing it will be easy enough.  Thanks for your help and input on this.  I wasn't sure the scope of what would be needed to do such a problem.

## Create an account

Register a new account