Q46 of 65 Page 24

A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with HCl and NaOH.

The metal A is Aluminum , B is Al2O3


The reaction is:
Al2O3 + 6HCl → 2AlCl3 + 3H2O
Al2O3 + 2NaOH → 2NaAlO2 + H2O


Metal A is aluminium (Al) that is used in the thermite process. Al reacts with oxygen to form aluminium oxide [Al2O3 (B)], which is amphoteric in nature. Thus, aluminium oxide reacts both as a base and as an acid.


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(c) Al and Cl2


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