Question

In the Baeyer's process, which of the following statements are incorrect?
(A) $ A{{l}_{2}}{{O}_{3}} $ goes into solution as soluble $ Al(OH)_{4}^{-} $ while other basic oxides as $ Ti{{O}_{2}} $ and $ F{{e}_{2}}{{O}_{3}} $ remain insoluble.
(B) $ A{{l}_{2}}{{O}_{3}} $ changes to $ AIN $ which in turn in decomposed by $ {{H}_{2}}O. $
(C) $ A{{l}_{2}}{{O}_{3}} $ changes to $ A{{l}_{2}}{{(C{{O}_{3}})}_{2}} $ which changes to $ AlC{{l}_{3}}. $
(D) $ A{{l}_{2}}{{O}_{3}} $ changes to $ A{{l}_{2}}{{(C{{O}_{4}})}_{2}} $ which changes to $ Al_{2}^{{}}{{S}_{3}}. $

Answer 1

Hint : We know that aluminium is a highly reactive metal belonging to the Periodic Table group $ ~IIIA $ . In nature, aluminium is found in its ores as its oxide. Bauxite, Corundum, Cryolite are the significant aluminium ores. It occurs through electrolysis.

Complete Step By Step Answer:
This results in a reduction in the melting point of the mixture and improves the capacity of the mixture to conduct electricity. A steel vessel is used with carbon and graphite lining rods. The carbon lining serves as a cathode, and the anode operates as graphite. Oxygen is formed in the anode when electricity is passed through the electrolytic cell that consists of carbon electrodes. This oxygen produced reacts to form carbon monoxide and carbon dioxide with the carbon of the anode.
Bayer's process: Bauxite ore contains impurities like $ F{{e}_{2}}{{O}_{3}},TiO_{2}^{{}},Si{{O}_{2}}~.~ $ When it dissolves in aq. $ NaOH $ /pressure $ +\text{ }150{}^\circ C $ , bauxite dissolves but the impurities do not.
 $ ~A{{l}_{2}}{{O}_{3}}+2NaOH\to 2NaAl{{O}_{2}}+{{H}_{2}}O $ and $ NaAl{{O}_{2}}+2{{H}_{2}}O\to Al{{\left( OH \right)}_{3}}+NaOH. $
Therefore, the correct answer is Option B, C and D.

Note :
Remember that Ferric oxide and silica are present in the bauxite ore as impurities. It is first concentrated by the magnetic separation process through the gravity separation, Leaching is the process in which an ore is treated with a suitable reagent as to make it soluble and the impurities remain insoluble. Baeyer’s process is the principle industrial method of refining ore.