Some Basic Principles Of Organic Chemistry Question 234
Question: In aluminum extraction by the Bayer’s process, alumina is extracted from bauxite by sodium hydroxide at high temperature and pressures. $ Al_2O_3(s)+2O{{H}^{-}}(aq)\to 2A{{l}^{-}}_2(aq)+H_2O(\ell ) $ Solid impurities such as $ Fe_2O_3 $ and $ SiO_2 $ are removed and then Al $ {{(OH)}^{-}}_4 $ is reprecipitated. $ Al{{(OH)}^{-}}_4\to Al_2O_3\cdot 2H_2O(s)+2O{{H}^{-}}(aq) $ In the industrial world
Options:
A) carbon dioxide is added to precipitate the alumina
B) Temperature and pressure are dropped and the super- saturated solution is seeded
C) both [a] and [b] are practiced
D) the water is evaporated.
Show Answer
Answer:
Correct Answer: C
Solution:
$ 2NaAlO_2+CO_2+2H_2O\to $ $ 2Al{{(OH)}_3}+2NaAl{{(OH)}_4} $
