Question

Is \[A{{l}_{2}}{{O}_{3}}\] Amphoteric?

Answer 1

Hint: We know that amphoteric oxide means, the metal oxide has a capability to react with both acid and base. Numerous metals like lead, zinc and aluminium form amphoteric oxides and they are highly reactive towards acid and bases.

Complete answer:
In following the trend we found that Acidity increases from left to right, ranging from strongly basic oxides on the left to strongly acidic ones on the right, with an amphoteric oxide aluminium oxide, in the middle. An amphoteric oxide is one which shows both acidic and basic properties. Aluminium oxide is an amphoteric oxide because it reacts with acids as well as bases and gives salts and water. Aluminium has electronegativity \[1.5.\] the electronegativity difference between aluminium and oxygen is small. Aluminium lies in group thirteen in the periodic table (electronegativity increases across a period). Aluminium oxide is insoluble in water and it is not reactive like sodium oxide and magnesium oxide. When we write aluminium oxide reaction we get to know that it is reacting with acid as well as base so we conclude that it has amphoteric nature means it can react with both acid and base.
Aluminium oxide thus will react with each acid in addition as bases. We’ll take the instance of its reaction with acid (strong acid) and hydroxide (strong base). Once mixed with these two compounds corundum either acts like acid with a base and a base with an acid.
\[A{{l}_{2}}{{O}_{3}}+6HCl\to 2AlC{{l}_{3}}+3{{H}_{2}}O~\] acts like a base.
\[Al2O3+2NaOH+3{{H}_{2}}O\to 2NaAl{{\left( OH \right)}_{4}}\] sodium aluminate acts like an acid.
On reacting \[A{{l}_{2}}{{O}_{3}}\] with \[HCl,\] we have a tendency to get chloride because the salt and water as a by-product. Likewise, the reaction between \[NaOH\] (robust Base) and \[A{{l}_{2}}{{O}_{3}}\] ends up in the formation of \[Na\] chemical compound as salt and water. So from the higher than reactions, we are able to conclude that they satisfy the neutralization reactions in addition.

Note:
Remember that the aluminium oxide is light, malleable, ductile, good conductor of electricity and heat. We come to know about the acidic and basic nature of any oxide only when we know that it is reacting with acid or base.