JIPMER 2015
- Exam
- JIPMER
- Year
- 2015
- Subject
- Chemistry
- Chapter
- General Principles and Processes of Isolation of Metals
JIPMER 2015 · Chemistry · General Principles and Processes of Isolation of Metals
The major role of fluorspar (CaF_2) which is added in small...
The major role of fluorspar which is added in small quantity in the electrolytic reduction of alumina dissolved in fused cryolite is
I. as a catalyst.
II. to make the fused mixture very conducting.
III. to lower the temperature of melting.
IV. to decrease the rate of oxidation of carbon at the anode.
Options
- AI, II
- BII, III
- CI, II, III
- DIII, IV
Correct answer
B. II, III
Step-by-step solution
Fluorspar is added in small quantity in the electrolytic reduction of alumina dissolved in fused cryolite to make the fused mixture more conducting and to lower the melting point of fused mixture at 1140 K .