Question

Which of the following oxides is amphoteric in character?
(A) $CaO$
(B) $C{{O}_{2}}$
(C) $Si{{O}_{2}}$
(D) $Sn{{O}_{2}}$

Answer 1

An attempt to this question can be made by understanding the term, 'amphoteric'. Amphoteric oxides react with acid as well as an alkali. Write reactions for the compounds given in options to determine if they are amphoteric in nature.

Complete step by step answer:
In chemistry, an amphoteric compound is defined as a molecule or an ion that has the ability to react with both acids as well as bases.
Adding to this, metal oxides that react with both acids and bases to produce respective salts and water are known as amphoteric oxides.
We will now evaluate the nature of the compounds given in options.
(A) $CaO$ is a metal oxide that is basic in nature.
(B) $C{{O}_{2}}$ is a non-metal oxide that is acidic in nature.
(C) $Si{{O}_{2}}$ is a metalloid oxide that is acidic in nature as well.
(D) $Sn{{O}_{2}}$ is a metal oxide that reacts with both acids and bases and is thus amphoteric in nature.
Based on the above statements we can conclude that the oxide that is amphoteric in nature is $Sn{{O}_{2}}$.

Therefore, the correct answer is option (D).

Note: It is important to understand the difference between amphoteric compounds and amphiprotic species as they are often mistaken to be the same. Amphoteric compounds react with acids as well as bases. On the other hand, amphiprotic species have the ability to accept as well donate positive hydrogen ions. Keep this in mind in order to avoid confusion between the two species.