CBSE Class 10 Science 2015 Term I Set 2

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Question : 5
Total: 36
A metal ' M ' is found in nature as its carbonate. It is used in the galvanization of iron. Identify ' M ' and name its ore. How will you convert this ore into free metal ?
Solution:  
M= Zinc metal
Zinc occurs as Zinc Carbonate in calamine ore, ZnCO3.
Zinc can be extracted from the ore by :
(i) Zinc Carbonate is first converted into Zinc Oxide by calcination. When calamine ore (zinc carbonate) is heated strongly in the absence of air, it decomposes to form zinc oxide and carbon dioxide.
ZnCO3
(Calamine ore)
Calcination
ZnO
(s)
+CO2

(ii) Zinc metal is then extracted from zinc oxide by reduction with carbon (coke).
ZnO(s)
Zinc oxide
+
C(s)
(Coke)
Zn(s)
Zinc metal
+
CO
Carbon monoxide
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