From the following, the correct statements about the role of substances added in the froth flotation process are:
a. | Collectors enhance the non-wettability of the mineral particles. |
b. | Collectors enhance the wettability of gangue particles. |
c. | By using depressants in the process, two sulphide ores can be separated. |
d. | Froth stabilisers decrease the wettability of gangue. |
1. a and b
2. b and c
3. c and d
4. a and c
From the following, the ores that are concentrated by froth flotation are:
a. | Haematite | b. | Galena |
c. | Copper pyrites | d. | Magnetite |
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d
Reactions among the following that occur during calcination are:
a. | CaCO3 → CaO + CO2 |
b. | \(\frac{11}{2}\)O2 → Fe2O3 + SO2 | 2FeS2 +
c. | Al2O3.xH2O → Al2O3 + xH2O |
d. | \(\frac{3}{2}\)O2 → ZnO + SO2 | ZnS +
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and c
Match the items in Column I with the items in Column II and assign the correct code.
Column I | Column II |
A. Pendulum | 1. Chrome steel |
B. Malachite | 2. Nickel Steel |
C. Calamine | 3. Na3AlF6 |
D. Cryolite | 4. CuCO3. Cu (OH)2 |
5. ZnCO3 |
Codes
A | B | C | D | |
1. | 1 | 2 | 3 | 4 |
2. | 2 | 4 | 5 | 3 |
3. | 2 | 3 | 4 | 5 |
4. | 4 | 5 | 3 | 2 |
Match the items in Column I with the items in Column II and assign the correct code.
Column I | Column II |
A. Coloured Bands | 1. Zone refining |
B. Impure metal to volatile complex | 2. Fractional distillation |
C. Purification of Ge and Si | 3. Mond’s process |
D. Purification of mercury | 4. Chromatography |
5. Liquation |
Codes
A | B | C | D | |
1. | 1 | 2 | 3 | 4 |
2. | 4 | 3 | 1 | 2 |
3. | 3 | 4 | 2 | 1 |
4. | 5 | 4 | 3 | 2 |
Match the items in Column I with the items in Column II, and assign the correct code.
Column I | Column II |
A. Cyanide process | 1. Ultrapure Ge |
B. Froth flotation process | 2. Dressing of ZnS |
C. Electrolytic reduction | 3. Extraction of Al |
D. Zone refining | 4. Extraction of Au |
5. Purification of Ni |
Codes
A | B | C | D | |
1. | 4 | 2 | 3 | 1 |
2. | 2 | 3 | 1 | 5 |
3. | 1 | 2 | 3 | 4 |
4. | 3 | 4 | 5 | 1 |
Assertion (A): | Nickel can be purified by Mond’s process. |
Reason (R): | It is a volatile compound that decomposes at 460 K to give pure Ni. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | Zirconium can be purified by the van Arkel method. |
Reason (R): | ZrI4 is volatile and decomposes at 1800 K. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
In the extraction of aluminium by the Hall-Heroult process, purified is mixed with to:
a. | Lower the melting point of |
b. | Increase the conductivity of the molten mixture. |
c. | Reduce into |
d. | Act as a catalyst |
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d
Which of the following metals can be purified by electrolytic refining?
1. Cu, and Zn
2. Ge, and Si
3. Zr, and Ti
4. Zn, and Hg