Question

Describe the acid-base character of the oxides of the period 3 elements Na to Ar. For sodium oxide and Sulphur Trioxide, write balanced equations to illustrate their acid-base character.

Answer 1

$Na_2O + H_2O$ → $2NaOH$

Explanation:

• The trend in the acid-base character is from strongly basic oxides to strongly acidic ones on moving from the left-hand side to the right-hand side in the periodic table.

• Moving from Na to Ar in middle an amphoteric oxide (aluminum oxide) is present.

• The element which shows both acidic and basic properties is known as amphoteric oxide.  

1. Sodium oxide

• Sodium oxide is a strong basic oxide which is due to the presence of the oxide ion, $O_2^{-}$.

• It is a very strong base having a greater tendency to combine with hydrogen ions.

• Sodium oxide when reacts with water  releases heat energy, it produces sodium hydroxide as a product.

$Na_2O + H_2O$ → $2NaOH$

• Sodium oxide also reacts with acids due to its basic nature.

• It when gives reaction with dilute hydrochloric acid produces sodium chloride and water as a product.

$Na_2O + 2HCl$ → $2NaCl +H_2O$

     2. Sulphur trioxide

• Sulfur trioxide reacts violently or explosively with water to produce concentrated sulphuric acid.

$SO_3 + H_2O$ → $H_2SO_4$