AgCl on fusion with sodium carbonate, gives:
1.
2.
3.
4.
Ore of Y would be:
(a) Siderite
(b) Cinnabar
(c) Malachite
(d) Hornsilver
Leaching of Ag2S is carried out by heating it with a dilute solution of:
1. NaCN only
2. HCl
3. NaOH
4. NaCN in presence of O2
Leaching is commercially carried out for in the concentration of:
(1) Galena
(2) Argentite
(3) Copper pyrites
(4) tin stone
NaCN is sometimes added in the froth flotation process as depressant when ZnS and PbS minerals are expected because:
1. is precipitated while no effect on ZnS
2. ZnS forms soluble complex while PbS forms froth
3. PbS forms soluble complex while ZnS forms froth
4. NaCN is never added in froth floatation process
Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.
(i) In Gold schmidt thermite process aluminium acts as a reducing agent.
(ii) Mg is extracted by electrolysis of aq. solution of
(iii) Extraction of Pb is possible by carbon reduction method
(iv) Red Bauxite is purified by Serpeck's process
(1) TTTF
(2) TFFT
(3)FTTT
(4) TFTF
A substance that can act as collector in the froth floatation method is -
1. Sodium xenate.
2. Sodium pyrophosphate.
3. Sodium nitroprusside.
4. Sodium ethyl xanthate.
(chromite) is converted to Cr by following steps :
Reagents in I, II and III step might be:
I-Step II-Step III-Step
(a) C C
(b)NaOH/air, C, Al,
(c) C, C,
(d)conc.
What is the composition of the anode mud used in the electrolytic refining of silver?
1. Zn, Cu, Ag, Au
2. Zn, Ag, Au
3. Cu, Ag, Au
4. Au only
Incorrect statement for the Hall-Heroult process is:
1. | Cryolite Na3AlF6 lower the melting point of Al2O3, and increase its electrical conductivity. |
2. | Al is obtained at the cathode, and CO2 at the anode. |
3. | Li2CO3 can be used in place of cryolite(Na3AIF6) |
4. | MgF2 can be used in place of fluorspar (CaF2) |