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Aluminium is extracted from alumina (Al₂O₃) by electrolysis of a molten mixture of
Options
(a) Al₂O₃ + HF + NaAlF₄
(b) Al₂O₃ + CaF₂ + NaAlF₄
(c) Al₂O₃ + Na₃AlF₆ + CaF₂
(d) Al₂O₃ + KF + Na₃AlF₆
Correct Answer:
Al₂O₃ + Na₃AlF₆ + CaF₂
Explanation:
Electrolytic mixture contains alumina (Al₂O₃), cryolite (Na₃AlF₆) and fluorspar(CaF₂) in the ratio of 20 : 40 : 20. Due to presence of these conductivity of alumina increases and fusion temperature decreases from 2000⁰C to 900⁰C.
Related Questions: - A sample of CaCO₃ is 50% pure. On heating 1.12 L of CO₂ at STP is obtained
- Ethyl iodide when heated with sodium in dry ether gives pure
- In the van der Waals equation, ‘a’ signifies
- The conductivity of strong electrolyte
- According to Bohr’s theory, the angular momentum of electron in 5th orbit is
Topics: Surface Chemistry and Isolation of Elements
(88)
Subject: Chemistry
(2512)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A sample of CaCO₃ is 50% pure. On heating 1.12 L of CO₂ at STP is obtained
- Ethyl iodide when heated with sodium in dry ether gives pure
- In the van der Waals equation, ‘a’ signifies
- The conductivity of strong electrolyte
- According to Bohr’s theory, the angular momentum of electron in 5th orbit is
Topics: Surface Chemistry and Isolation of Elements (88)
Subject: Chemistry (2512)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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