Question

In the leaching method, bauxite ore is digested with a concentrated solution of naoh that produces x. When co2 gas is passed through the aqueous solution of x, a hydrated compound y is precipitated. x and y respectively are :

Answer 1

The Sodium hydroxide dissolves oxides of Aluminium and Silicon present in Bauxite.

The solution now contains Oxides of Aluminium and Silicon.

When Carbon(iv)oxide is bubbled through the solution a weak carbonic acid is formed.

The weak carbonic acid neutralizes the Sodium hydroxide present from the previous treatment.

The neutralization selectively precipitates Aluminium Oxide leaving behind the silicates in solution.

Therefore:

X — Aluminium oxide and Silicon oxide solution

Y — Aluminium oxide precipitate.