Consider a mixture of water, sand, and oil. How many phases are present? How could you separate mixture into individual substances?

1 Answer
Jun 19, 2017

Technically 2 different phases, as sand is solid but water and oil are both liquid. But water and oil are immiscible, so physically there are 3 distinct phases.


1) Pass the mixture through a filter mesh, this will separate the sand from the oil/water mixture. The sand can then be washed with some solvent to remove any traces of oil, and then dried out.

2) Place the oil/water mixture into a separating flask with a bottom tap, and let it stand undisturbed for an hour or so. The two liquids will separate into two distinct layers with the lower density oil floating above the higher density water (oils have densities below 1.00 g/ml). Open the tap and carefully run out the water later, leaving the oil layer in the flask.