Copper (II) sulphate pentahydrate is a crystalline solid with a beautiful bright blue colour. Like most sulphate salts, it dissolves well in water. If you want or need to separate copper sulphate from sand -- either as a classroom experiment or because you accidentally mixed the one with the other -- you can take advantage of this compound's properties to take the two apart.
Pour the sand and copper sulphate into one of the two buckets.
Pour water into the bucket until it covers the sand and copper sulphate mixture. The copper sulphate should begin to dissolve; stir if you need to make it dissolve more rapidly.
Place the paper filter in the funnel. Holding the funnel over the second bucket, pour the mixture through it. The dissolved copper sulphate will pass through the filter, while the sand will remain behind. The solution you have in the second bucket contains copper sulphate only.
- "Chemical Principles, the Quest for Insight, 4th Edition"; Peter Atkins and Loretta Jones; 2008