Chemistry · Importance of coordination compounds (in qualitative analysis, extraction of metals and in biological systems)

In the extraction of aluminium by electrolytic process, cryolite is added to

In the extraction of aluminium by electrolytic process, cryolite is added to

  • A. lower the melting point of alumina
  • B. increase the electrical conductivity
  • C. minimise the anode effect
  • D. remove impurities from alumina

Step-by-step solution

In the Hall-Héroult process for aluminium extraction, cryolite (Na3AlF6) is added to alumina (Al2O3) to lower its melting point from about 2000°C to around 950°C, making the electrolytic process feasible. While it also increases electrical conductivity, the primary purpose is to lower the melting point.
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