An electrochemical process is used to extract:

1. Iron

2. Lead

3. Sodium

4. Silver

In the commercial electrochemical process for aluminum extraction, the electrolyte used as:

$\left(1\right)<mspace\; width="1em"></mspace>AI{\left(OH\right)}_3<mspace\; width="1em"></mspace>in<mspace\; width="1em"></mspace>NaOH<mspace\; width="1em"></mspace>solution$
$$
$\left(2\right)<mspace\; width="1em"></mspace>An<mspace\; width="1em"></mspace>aqueous<mspace\; width="1em"></mspace>solution<mspace\; width="1em"></mspace>of<mspace\; width="1em"></mspace>A{I}_2{\left(S{O}_4\right)}_3<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$
$$
$\left(3\right)<mspace\; width="1em"></mspace>A<mspace\; width="1em"></mspace>molten<mspace\; width="1em"></mspace>mixture<mspace\; width="1em"></mspace>of<mspace\; width="1em"></mspace>A{I}_2{O}_3<mspace\; width="1em"></mspace>and<mspace\; width="1em"></mspace>N{a}_{3}AI{F}_6$
$$
$\left(4\right)<mspace\; width="1em"></mspace>A<mspace\; width="1em"></mspace>molten<mspace\; width="1em"></mspace>mixture<mspace\; width="1em"></mspace>of<mspace\; width="1em"></mspace>AIO\left(OH\right)<mspace\; width="1em"></mspace>and<mspace\; width="1em"></mspace>AI{\left(OH\right)}_3$

Electrolytic reduction of alumina to aluminium by Hall-Heroy process is carried out:

(1) In the presence of NaCl

(2) In the presence of fluorite

(3) In the presence of cryolite which forms a melt with lower melting temperature

(4) In the presence of cryolite which forms a melt with higher melting temperature

The methods chiefly used for the extraction of lead and tin from their ores respectively:

(1) Self reduction and carbon reduction

(2) Self reduction and electrolytic reduction

(3) Carbon reduction and self reduction

(4) Cyanide process and carbon reduction

Which ore contains both iron and copper ?

1. Cuprite

2. Chalcocite

3. Chalcopyrite

4. Malachite

What method is used to extract zinc from zinc blende?

1. Electrolytic reduction

2. Roasting followed by reduction with carbon

3. Roasting followed by reduction with another metal

4. Roasting followed by self-reduction

Native silver metal forms a water-soluble complex with a dilute aqueous solution of NaCN in the presence of:

1. Nitrogen

2. Oxygen

3. Carbon Dioxide

4. Argon

Oxidation states of the metal in the minerals haematite and magnetite, respectively, are

(1) II, III in haematite and III in magnetite

(2) II, III in haematite and II in magnetite

(3) II in haematite and II, III in magnetite 

(4) III in haematite and II, III in magnetite 

Extraction of metal from the ore cassiterite involves

(1) Carbon reduction of an oxide ore

(2) Self-reduction of a sulphide ore

(3) Removal of copper impurity

(4) Removal of iron impurity

Iron is extracted from chalcopyrite as :

1. FeO
2. FeS
3. Fe₂O₃
4. FeSiO₃