Specification Point 1.60C (Paper 2C Only):
Practical: investigate the electrolysis of aqueous solutions
Electrolysis of Aqueous Solutions
Electrolysis: Decomposition of an ionic substance by passing an electric current through it
The electrolysis of aqueous solutions
- Add Aqueous solution into a beaker.
- Add two graphite rods as the electrodes and connect this to a power pack or battery.
- Turn on power pack or battery and allow electrolysis to take place.
- Can investigate if solution is an electrolyte by including a bulb in the circuit. If the bulb lights up the substance can conduct electricity and it is an electrolyte.
- An investigation into the products formed at each electrode can be done:
- If a solid forms around the electrode, the metal ions have been deposited. Colour can give away what metal.
- If the gas produced at the cathode burns with a ‘pop’ when a sample is lit with a lighted splint. This shows that the gas is hydrogen.
- If the gas produced at the anode relights a glowing splint dipped into a sample of the gas. This shows that the gas is oxygen.
If the gas is coloured it is likely a halogen gas: Brown gas is bromine. Yellow-green gas is chlorine.
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Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.
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