Study the relative reactivity of metals like iron and copper
- Iron nails
- 5% Copper sulphate
- Dilute sulphuric acid
- Test tube holder
- Test Tubes
- Take the beaker and add about 20mL of water in it
- Pour about a 2gm of copper sulphate in water and shake well to dissolve it
- Add a 4-5 drops of dilute sulphuric acid to the solution by using dropper
- Drop an iron piece (nail, blade, etc.) into the solution
- After nearly half an hour observe the change in the colour of blade as well as of copper sulphate solution
- The blue colour solution of copper sulphate first fades and then changes to green and a brown deposit is formed on the shaving blade.
- Copper metal which is brown in colour is deposited on shaving blade due to its displacement from copper sulphate by iron.
- Green colour of the solution is due to the formation of iron sulphate.
- Copper sulphate (blue) + Iron (grey) → Iron sulphate (light green) + Copper (brown)
- Different metals have different reactivities with chemical reagents. The metals that form positive ions by losing electrons more readily. A more reactive metal displaces a less reactive metal from salt solution. Such reactions are called displacement reactions.
- Aluminium is more reactive than zinc.
- Zinc is more reactive than Fe.
- Fe is more reactive than Cu.
The below table gives you an understanding of the colours exhibited by the metals and their salts:
|Ferrous sulphate||FeSO4||Light green|