Thursday 11 February 2016

Science: Experimenting with Copper Sulphate

First of all Heating copper...
One of my friends who come along to my science groups back in 2012,  asked me if we could do some experiments on heating materials.  She said she had tried heating a copper coin and couldn’t get it to spark green and didn’t know why.  Well, this is why it didn't produce that green flame...
If you heat a modern copper coin it will go black, no green flame.  This is because you have formed copper oxide; the black formed during the heating of the coin in flame is the copper oxide. 

When it is cooled down obviously, you can clear away the copper oxide.

Then I was left with the question: how could I make a green flame using copper?  How I did this was not using a copper coin But I did use  copper sulphate.  Using a spoon and an alcohol burner I heated it and voila green flames!  Fab.  Be sure that you’re in a ventilated area when you do this.
What else can we do with Copper sulphate? 

We could put an iron nail in it.  What happens?  The liquid turns from blue to green.

When an iron nail is placed in a copper sulphate solution, iron displaces copper from copper sulphate solution forming iron sulphate, which is green in colour.

Therefore, the blue colour of copper sulphate solution fades and green colour appears.

When we take an iron metal nail and dip it into a blue solution of copper (II) sulphate, firstly it changes the solution to iron sulphate which is green in colour.  If you leave it the nail becomes covered with a reddish substance. This reddish substance is metallic copper. The equation for this is:

Fe(s) + CuSO4(aq) -> FeSO4(aq) + Cu(s)

This is what is known as a redox reaction, or otherwise known as a oxidation reduction reaction.

This post was first written 11/07/2012 revised: 11/02/2016


  1. We had great fun creating loads of different colour flames and sparks when we made gunpowder. Different chemicals give different colours:
    Red Strontium Chloride or Strontium Nitrate
    Orange Calcium Chloride
    Yellow Sodium Chloride (table salt) or Borax
    Green Copper Sulfate or Boric Acid
    Blue Copper Chloride
    Purple Potassium Chloride
    White Magnesium Sulfate (Epsom salts)
    Girls want to make fireworks next, think we'll start with sparklers...

  2. We've done a few of them on Monday and yes iron filings are fun - Chiara wants to do a video of heating iron filings soon, they were a big hit at Monday group too. You know I'm going to have to look into making sparklers now! That sounds like too much fun to miss! Thank you x