Explain the process of coating copper on iron key. Draw the circuit diagram.

Question

Philoid · Accepted Answer

Coating an iron key with copper by electroplating method:

i. Dissolve crystals of copper sulphate in pure water to prepare concentrated solution (deep blue in colour)

ii. Pour the solution in a beaker and add a few drops of dilute sulphuric acid to it.

Note: Acid helps in increasing the conductivity of electrolyte.

iii. Tie one end of a connecting copper wire to the iron object (key) to be coated with copper.

iv. Connect its other end to the negative terminal of a battery.

v. Suspend the tied iron object into the copper sulphate solution.

vi. Suspend the copper plate into copper sulphate from positive end of the battery through a switch as shown in figure.

We observe that:

i. When electric current is passed, the free copper ions from the copper sulphate solution goes to the electrode of iron.

ii. The copper ions get deposited on the iron key.

iii. As a result, the iron key get coated with copper. This is the process of electroplating.