A pair of metals among the following that can be purified by the van Arkel method are:
1. Zr, and Ti
2. Ag, and Au
3. Ni, and Fe
4. Ga, and In
4M + 8CN- + 2H2O + O2 4[M(CN)2]- + 4OH-
2[M(CN)2]- + Zn[Zn(CN)4]2- + 2M
The metal M in above-mentioned reaction is:
1. Nickel
2. Silver
3. Copper
4. Mercury
The extraction of gold and silver involves leaching with CN- ion. Silver is later recovered by:
1. Liquation
2. Distillation
3. Zone refining
4. Displacement with Zn
A major impurity in pig iron is:
1. Carbon
2. Silicon
3. Phosphorus
4. Manganese
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
Aluminium is extracted from alumina Al2O3 by electrolysis of a molten mixture of:
1.
2.
3.
4.
Brine is electrolysed by using inert electrodes. The reaction at the anode is:
1. Cl-(aq) → \(\frac{1}{2}\)Cl2(g) + e-; \(E_{cell}^{o}\) = 1.36 V
2. 2H2O(l) → O2(g) + 4H+ + 4 e-; \(E_{cell}^{o}\) = 1.23 V
3. Na+(aq) + e- → Na(s); \(E_{cell}^{o}\) = 2.71 V
4. H+(aq) + e- → \(\frac{1}{2}\)H2(g); \(E_{cell}^{o}\) = 0.00 V
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
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
The correct match among the following is:
Column I | Column II |
(a) Boron | (i) Van Arkel method |
(b) Tin | (ii) Mond's process |
(c) Zirconium | (iii) Liquation |
(d) Nickel | (iv) Zone refining |
(a) | (b) | (c) | (d) | |
1. | (iv) | (iii) | (i) | (ii) |
2. | (iv) | (iii) | (ii) | (i) |
3. | (ii) | (i) | (iv) | (iii) |
4. | (iii) | (iv) | (i) | (ii) |