The Grass Doctor

How do you separate sand, copper sulfate and urea?

We're given a mixture of sand, copper sulfate and urea (a valuable fertilizer) in a film canister We have to separate them and find what weight of each substance was present in the mixture Here is some information about the 3 substances: Urea: Colour: white. Soluble in both water and meths Copper sulfate: Colour: blue. Only soluble in water Sand: Colour: yellow. Insoluble in both water and meths You may have 30mL of meths and 30mL of distilled water At the end of this (since we are going to do this in class) you should have the copper sulfate, sand and urea separated and dry so they can be individually weighed. There will be a prize for the person that is closest to the weighs that have been measured into the sample jar. If ANYONE knows how to separate this mixture please write down the method All answers appreciated Thank you

Public Comments

1. Should be easy. First, wash with meths. This will dissolve out the urea. Next wash with water. This will dissolve out the the copper sulfate. You'll be left with the sand. Weigh everything after each step (that way you might be able to back out some numbers if you need to), and collect the filtrate. Make sure to carefully, and completely mix everything at each 'wash' step. Boil off the excess solvent. Weigh the end products.