NCERT Class XII Chemistry
Chapter - General Principle of Process of Isolation of Elements
Questions with Solutions
© examsnet.com
Question : 14
Total: 31
Giving examples, differentiate between ‘roasting’ and ‘calcination’.
Solution:
Calcination : It is the process of converting an ore into its oxide byheating it strongly below its melting point either in absence or limitedsupply of air.
F e 2 O 3 . x H 2 O
F e 2 O 3 + x H 2 O
Z n C O 3 ( s )
Z n O ( s ) + C O 2 ( g )
Roasting : In roasting, the ore is heated in a regular supply of air in afurnace at a temperature below the melting point of the metal.
2 Z n S + 3 O 2 – – – – – – ▶ 2 Z n O + 2 S O 2
2 P b S + 3 O 2 – – – – – – ▶ 2 P b O + 2 S O 2
Roasting : In roasting, the ore is heated in a regular supply of air in afurnace at a temperature below the melting point of the metal.
© examsnet.com
Go to Question: