Given below are two statements:
Assertion (A): | Magnesium metal is not used for the reduction of alumina in the metallurgy of aluminum |
Reason (R): | Magnesium can reduce alumina. But the process will be uneconomical. |
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): | Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal. |
Reason (R): | Copper is extracted by hydrometallurgy. |
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): | The zone refining method is very useful for producing semiconductors. |
Reason (R): | Semiconductors are of high purity. |
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. |
Given below are two statements:
Assertion (A): | Sulphide ores are concentrated by the froth flotation method. |
Reason (R): | Cresols stabilise the froth in the froth flotation method. |
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. |
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. |
Given below are two statements:
I: | The Ellingham diagram provides an idea about the feasibility of a reaction. |
II: | The Ellingham diagram explains the rate of the reduction reactions. |
In light of the above statements, choose the most appropriate answer from the options given below:
1. | I is correct and II is incorrect. |
2. | I is incorrect and II is correct. |
3. | Both I and II are correct. |
4. | Both I and II are incorrect. |
Among statements (I) – (IV), the correct ones are-
(I) | Limestone is decomposed to CaO during the extraction of iron from its oxides |
(II) | In the extraction of silver, silver is extracted as an anionic complex |
(III) | Nickel is purified by Mond's process |
(IV) | Zr and Ti are purified by the Van Arkel method |
1. (III) and (IV) only
2. (I), (III), and (IV) only
3. (II), (III), and (IV) only
4. (I), (II), (III), and (IV)
Which of the following statements are correct?
a. A depressant prevents certain types of particles to come to the froth.
b. Copper matte contains and .
c. The solidified copper obtained from the reverberatory furnace has a blistered appearance due to the evolution of during the extraction.
d. Zinc can be extracted by self-reduction.
Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, c)
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