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Question
In the extraction of Al, impure Al2O3 is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?
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Solution
In the extraction of aluminium, impure Al2O3 is dissolved in concentrated NaOH to form NaAlO2. This method is known as leaching of alumina.
Al2O3(s) + 2 NaOH(aq) + 3 H2O(l) → 2 Na[Al(OH)4](aq)
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