Q. No.The correct statement for the reduction of FeO at the temperature corresponding to point D is:
1.
∆G value for the overall reduction reaction with carbon monoxide is zero.
2.
∆G value for the overall reduction reaction with a mixture of 1 mol carbon, and 1 mol oxygen is positive.
3.
∆G
value for the overall reduction reaction with a mixture of 2 mol of carbon, and 1 mol of oxygen will be positive.
4.
∆G value for the overall reduction reaction with carbon monoxide is negative.
Consider the following figure
At the temperature corresponding to which of the points FeO will be reduced to Fe by coupling the reaction 2FeO →2Fe + O2 with all of the following reactions?
(i) C + O2 →CO2
(ii) 2C + O2 → 2CO
(ii) 2CO + O2 → 2CO2
a. Point A
b. Point B
c. Point D
d. Point E
Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)
Which of the following statement is correct?
| 1. | Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast. |
| 2. | In the extraction of silver, silver is extracted as a cationic complex. |
| 3. | Nickel is purified by zone refining. |
| 4. | Zr, and Ti are purified by the van Arkel method. |
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)
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. | 2FeS2 + \(\frac{11}{2}\)O2 → Fe2O3 + SO2 |
| c. | Al2O3.xH2O → Al2O3 + xH2O |
| d. | ZnS + \(\frac{3}{2}\)O2 → ZnO + SO2 |
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
© 2024 GoodEd Technologies Pvt. Ltd.