Question

Calcination is a process in which the ore is heated strongly in the absence of air to remove volatile impurities. It thermally decomposes the carbonate.
$A{l}_2{O}_3.2H_{2}O\stackrel{Calcination}{\to }B+2H_{2}O$
The name of product $B$ is:

• A. Corundum
• B. Bauxite
• C. Aluminum hydroxide
• D. None of these

Answer 1

The correct option is A Corundum

$A{l}_2{O}_3.2H_{2}O\stackrel{Calcination}{\to }A{l}_2{O}_3+2H_{2}O$

Here, $A{l}_2{O}_3$ is called corundum.

Corundum is a crystalline form of aluminium oxide $A{l}_2{O}_3$ that usually contains traces of iron, titanium, vanadium, and chromium. It is a rock-forming mineral that is naturally transparent. Different transition metal impurities present in the structure could impart different colors. The mineral corundum has two principal gem varieties - sapphire and ruby. chromium impurities impart the deep red shade that characterizes rubies. On the other hand, sapphires could display a range of hues depending on the type of transition metal present in the structure.