Required Practical: Electrolysis  

This experiment is used to understand and observe the reactions occurring during the ELECTROLYSIS of various aqueous solutions using INERT ELECTRODES.

Equipment and Materials:

• TEST TUBES OR MEASURING CYLINDERS: To collect and measure gases produced at the electrodes.
• ELECTROLYTE SOLUTIONS: Aqueous solutions that will undergo electrolysis.
• BEAKER: To hold the electrolyte during electrolysis.
• GRAPHITE ELECTRODES: Inert electrodes that conduct electricity without reacting.
• POWER SUPPLY: To provide a controlled electric current.

Method:

• Choose an ELECTROLYTE. 
• Pour out a sample of the electrolyte into the beaker.
• Immerse two INERT electrodes into the solution and place an INVERTED TEST TUBE over each electrode.
• Pass CURRENT through the electrolyte and collect the gases in the inverted test tubes or measuring cylinders.
• Use CHEMICAL TESTS to identify the gases produced.

TEST FOR GASES

1. Chlorine:

Add DAMP BLUE LITMUS PAPER to the gas.

If the litmus paper BLEACHES WHITE, Chlorine is present.

2. Oxygen:

Add a GLOWING SPLINT to the gas.

If the glowing splint RELIGHTS, Oxygen is present.

3. Hydrogen

Add a LIT SPLINT to the gas.

If a SQUEAKY POP is observed, Hydrogen gas is present.