Chemistry : Part I for Class XII
General Principles and Processes of Isolation of Elements - 01

Instructions 

1. All questions are compulsary.
2. Please give the explanation for the answer where applicable.
3. To view the answer, click on the Answer link alongside the Question.
You can view the answer when the link becomesGreen Red. on completion of allocated time.


Q.1) Give the name and composition of the ore chosen for extraction of aluminium. (1 Marks) 

Q.2) What is leaching? (1 Marks) 

Q.3) Why are cryolite and fluorospar added to alumina during electrolytic reduction? (1 Marks) 

Q.4) What are minerals and how are they different from ores? (2 Marks) 

Q.5) Name one ore each for iron and copper and give their chemical compositions. (2 Marks) 

Q.6) Explain the process of magnetic separation for the concentration of ores. (3 Marks) 

Q.7) What is the purpose of adding collectors and froth stabilisers during froth floatation?Give an example for each. (2 Marks) 

Q.8) How can the ores ZnS and PbS be separated from a mixture using froth floatation process? (2 Marks) 

Q.9) Differentiate between roasting and calcination. (3 Marks) 

Q.10) What is the impurity present in iron oxide during reduction? How can it be removed? (3 Marks)