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 The iron nails are the two electrodes. Connect the two terminals of a battery to the two iron

nails by including a compass and a switch in the circuit.

 Pass the electric current through cut potato piece by closing the switch.
 We will observe a deflection in the compass needle showing that potato conduct electricity to

some extent.

 Let us continue to pass electric current through potato piece for about half an hour.
 We will observe a greenish blue spot on the cut surface of potato around the iron nail which

is connected to the positive terminal of the battery.
 The formation of a greenish blue spot around the positive electrode inserted in the surface of

a cut potato shows that the chemical effect of current can bring about change in the colour of
a conducting solution.

APPLICATIONS OF THE CHEMICAL EFFECT OF ELECTRIC CURRENT:

The chemical effect of an electric current is widely used in industries or factories for the following

purposes:

1) Electroplating metals,

2) Purification of metals,
3) Production of certain metals from the ores,

4) Production of chemical compounds, and
5) Decomposing chemical compounds.

Out of the above listed applications, we will be studying Electroplating in detail, in the next module.

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