Introduction to Electrolysis
In metals and carbon, electricity and electric current is simply a flow of electrons or ions. Electrolysis is the chemical change caused by passing an electric current through a compound which is either molten or in a solution. An electrolyte is a substance that undergoes electrolysis. It contains ions. It is the movement of the ions, which are responsible for both the conduction of electricity and the chemical changes that take place. Covalent compounds are not electrolytes and don’t conduct electricity because they have no free moving electrons. Ionic compounds only conduct electricity when molten or in a solution because the ions separate and are free to move. These particles can then carry the electric current.
| Experiment to distinguish between electrolytes and non-electrolytes
i. Dissolve substance in water, or if possible, melt it. ii. Put a conductivity tester into the substance. iii. If the light bulb lights up, it is an electrolyte.
Explain: When dissolved in water, free moving electrons are able to carry the electric current across from the cathode to the anode, completing the circuit and lighting the bulb. If the light bulb does not light up, the substance is obviously not an electrolyte.
But sugar dissolves, why does the bulb not light up? Sugar is a covalent structure.
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