Match items of Column I with the items of Column II and assign the correct code.
Column l Column II
A. Cyanide process 1. Ultrapure Ge
B. Froth floatation 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
(a) 2 3 1 5
(b) 1 2 3 4
(c) 3 4 5 1
(d) 4 2 3 1
Aluminium is extracted from alumina (Al2O3) by electrolysis of a molten mixture of :
1. Al2O3 + HF + NaAlF4
2. Al2O3 + CaF2 + NaAlF4
3. Al2O3 + Na3AlF6 + CaF2
4. Al2O3 + KF +Na3AlF6
During extraction, copper is obtained by the reduction of cupric oxide with:
1. Cu2S
2. SO2
3. FeS
4. CO
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
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
Consider the following reactions at 1000 oC.
(I) ZnS + 1/2O2(g) \(\xrightarrow[]{\Delta }\) ZnO(g); ∆Go = -360 kJ mol-1
(II) Cs + 1/2O2(g) \(\xrightarrow[]{\Delta }\) CO(g); ∆Go = -460 kJ mol-1
Choose the correct statement about the above reactions at 1000 oC:
1. ZnO is more stable than CO
2. ZnO can be reduced to Zn by C
3. ZnO, and CO are formed at an equal rate
4. ZnO can not be reduced to Zn by C
Chromium is obtained by reducing concentrated chromite ore with :
1. Red hot coke
2. Gaseous hydrogen
3. Aluminium powder
4. Carbon monoxide
Which is not correctly matched:
(1) spieglesian : Mn+Fe+C
(2) Dow's sea water process :
(3) parke's process :Ag
(4) liquation spelter(Impure Zn
Incorrect match is :
(a) Purification of Al :Baeyer's method
(b) polling :Reduction of
(C) (chromite ore) : NaOH/N
(d) Ag: Mac Arthur cyanideprocess