Question

Example of aluminium oxide reacting with both base and acid

Answer 1

Answer:

hello buddy!!

with acid :-

Al2o3 + 6Hcl ------> 2Alcl3 + 3H20

with base:-

Al2o3 + NaoH ------> Nao+ Al(0H)3

Answer 2

Answer:

Describing the properties of aluminium oxide can be confusing because it exists in a number of different forms. One of those forms is very unreactive. It is known chemically as alpha-Al2O3 and is produced at high temperatures.

In what follows we are assuming one of the more reactive forms.

Aluminium oxide is amphoteric. It has reactions as both a base and an acid

Reaction with water

Aluminium oxide doesn't react in a simple way with water in the sense that sodium oxide and magnesium oxide do, and doesn't dissolve in it. Although it still contains oxide ions, they are held too strongly in the solid lattice to react with the water.

Reaction with acids

Aluminium oxide contains oxide ions and so reacts with acids in the same way as sodium or magnesium oxides. That means, for example, that aluminium oxide will react with hot dilute hydrochloric acid to give aluminium chloride solution.

1. Al2o3 +6HCL gives 2ALCl3 + 3H2O

In this (and similar reactions with other acids), aluminium oxide is showing the basic side of its amphoteric nature.

Reaction with bases

Aluminium oxide has also got an acidic side to its nature, and it shows this by reacting with bases such as sodium hydroxide solution.

Various aluminates are formed - compounds where the aluminium is found in the negative ion. This is possible because aluminium has the ability to form covalent bonds with oxygen.

In the case of sodium, there is too much electronegativity difference between sodium and oxygen to form anything other than an ionic bond. But electronegativity increases as you go across the period - and the electronegativity difference between aluminium and oxygen is smaller. That allows the formation of covalent bonds between the two.

With hot, concentrated sodium hydroxide solution, aluminium oxide reacts to give a colourless solution of sodium tetrahydroxoaluminate.

Al2O3 + 2NaOH +3H2O gives 2NaAl(OH)4