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
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
In the froth flotation process, how can zinc sulphide and lead sulphide be separated?
a. Using collectors.
b. Adjusting the proportion of oil to water.
c. Using depressants.
d. Using froth stabilizers.
Choose the correct option:
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)
The common impurities present in bauxite are:
a.
b.
c.
d.
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d
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
Which of the following ores can be reduced by carbon?
a. Haematite
b. Zincite
c. Iron pyrites
d. Sphalerite
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d
The main reactions that occur in the blast furnace during iron extraction from hematite are:
a. | Fe2O3 + 3CO → 2Fe + 3CO2 |
b. | FeO + SiO2 → FeSiO3 |
c. | \(\xrightarrow[]{}\) 2Fe + 3CO | Fe2O3 + 3C
d. | \(\xrightarrow[]{}\) CaSiO3 | CaO + SiO2
Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d
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 |