Electrolysis

Electrolysis

Electrolysis is a chemical process by which electrical currents can be

passed through solutions. Pure water cannot conduct electricity, but

if a salt such as Sodium Chloride is dissolved in it, the solutions

will start conducting if two electrodes are placed in it with a

battery that provides the initial current.

When we close the switch, copper ions on the anode will start to move

through the solution to the cathode. The copper atoms have already

given up two electrons to become ions and their electrons are free to

move in the wires. Closing the switch pushes electrons clockwise and

forces some copper ions into the solution.

The cell pushes the ions from the anode to the cathode. At the same

time, it pushes the free electrons around the wires (these electrons

are already spread through the wires). Electrons in the cathode

recombine with copper ions from the solution, forming a new layer of

copper atoms.

Gradually, the anode is eroded and the cathode grows. Insoluble

impurities in the anode fall to the bottom in a pile. This valuable bi

product is removed.

Gold, silver, platinum and tin are insoluble in this electrolyte and

so do not deposit on the cathode. They form a 'sludge' that collects

under the anodes.

If the substance the metal rods are placed in is not in liquid form,

the current with not conduct.

To prove that electricity is flowing through the current, we could add

a working bulb to the circuit. If the is a current flowing, the bulb

will light up, but if there is no current flowing through the circuit,

the bulb will not light up. This is shown in a diagram below.

However, if there is a current, but it is quite a low voltage, the

bulb may not light up, despite there being an active current present.

We could overcome this problem by adding an ammeter to the circuit.

This would mean that the ammeter would be able to show us whether

there was a current in the circuit, and how strong the current is.