Electronic Conductivity - IGCSE Chemistry Revision Notes

Introduction to Conductivity

• Conductivity is the flow of charged particles.
• Electric current is typically the flow of electrons, but can also involve ions.

Conductivity of Covalent Compounds

• Most covalent compounds do not conduct electricity due to the lack of freely moving charged particles.
• Act as insulators; used in applications that require insulation (e.g., sulfur hexafluoride as an insulator in transformers).
• Common insulators include plastic coatings around electrical wiring.

Conductivity of Ionic Compounds

• Ionic compounds conduct electricity when in the molten state or in solution because ions are free to move and carry charge.
• Cannot conduct electricity in the solid state as ions are fixed in a lattice.

Cations and Anions

• Anions are negatively charged ions (e.g., Cl-, O2-, SO42-).
• Cations are positively charged ions (e.g., K+, Mg2+, H+).
• During electrolysis:
  • Electrons move from anode to cathode.
  • Cations migrate towards the cathode (negatively charged electrode).
  • Anions migrate towards the anode (positively charged electrode).

Exam Tips

• In metals, electrons move through the metal.
• In salt solutions, ions move towards electrodes while carrying electrons.

Additional Resources

• Electrolysis Experiments
• Writing Half-Equations

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