(a) In column I different methods of extraction are given. Name the methods used for the extraction of metals given in Column II: | |
Column - I | Column - II |
(i) Reduction with carbon | Al, Zn, Na, Fe, Mn, Pb |
(ii) Electrolytic reduction | |
(iii) Reduction with aluminium | |
(b) Differentiate between roasting and calcination processes giving one example of each. |
Answer:
(a)
Column ? I
Column ? II
(i) Reduction with carbon
Zn, Fe, Pb
(ii) Electrolytic reduction
Al, Na
(iii) Reduction with aluminium
Mn
(b) Difference between roasting and calcination.
Roasting
Calcination
1. Roasting is done in case of sulphide ores.
Calcination is done in case of carbonate ores.
2. In this, the ore is heated in the presence of excess air to convert it into its oxide compound.
The carbonate ore is heated in the absence of air (limited supply of air) to convert into its oxide.
3. The gas given out is \[S{{O}_{2}}\] (sulphur dioxide) gas.
The gas given out is \[C{{O}_{2}}\] (carbon dioxide) gas.
4. Example: \[2ZnS+\underset{(Air)}{\mathop{3{{O}_{2}}}}\,\xrightarrow{Heat}2ZnO+2S{{O}_{2}}\uparrow \]
Example: \[ZnC{{O}_{3}}\xrightarrow{Heat}ZnO+C{{O}_{2}}_{{}}\uparrow \]
You need to login to perform this action.
You will be redirected in
3 sec