Electrolysis of a Binary Compound in Molten State
Chemistry: Cambridge International GCSE Supplement, topic 4.1.3
Electrolysis of a Binary Compound in the Molten State
Electrolysis splits molten binary compounds using electricity. Positive ions go to the cathode (reduction), forming metal. Negative ions go to the anode (oxidation), forming non-metal.
Introduction to electrolysis of binary compounds
- Electrolysis splits molten binary compounds into elements using electricity.
- Binary compounds contain two elements, often metal and non-metal.
- Molten state means the compound is melted to allow ions to move.
- Electricity causes positive ions to go to cathode, negative ions go to anode.
Movement of ions during electrolysis
- Positive ions (cations) move to the cathode (negative electrode).
- Negative ions (anions) move to the anode (positive electrode).
- Electrolysis requires ionic movement for chemical changes at electrodes.
- This movement allows prediction of products formed at each electrode.
Predicting products at the electrodes
- At the cathode, cations gain electrons (reduction) to become atoms or molecules.
- At the anode, anions lose electrons (oxidation) to become atoms or molecules.
- For a molten binary compound, expect metal at cathode and non-metal at anode.
- Example: Electrolysis of molten sodium chloride produces sodium metal and chlorine gas.
Example of electrolysis of molten sodium chloride (NaCl)
- Sodium ions (Na+) move to cathode, gain electrons, form sodium metal (Na).
- Chloride ions (Cl-) move to anode, lose electrons, form chlorine gas (Cl2).
- This method produces pure sodium and chlorine through molten NaCl electrolysis.
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Summary and importance
- Electrolysis of molten binary compounds separates elements by electricity.
- It is possible to predict products based on ion movement and charge at electrodes.
- This technique is essential in metal extraction and chemical industries.
Test yourself on Electrolysis of a Binary Compound in Molten State
Why must a binary compound be in a molten state for electrolysis to occur effectively?