__________ acts as a reducing agent during the extraction of iron from the pyrites ore.

Bauxite is used to extract ___________.

Sulphide ores are extracted by __________.

104. State whether the following statements are true (T) or false (F):

A.

Sodium is found in the native state.

B.

Metals can be recovered from their ores by chemical methods.

C.

Metallic sodium is obtained by electrolysis of molten sodium chloride.

D.

In calcination, the ore is heated with calcium.

E.

In electrolytic refining of copper, pure copper is taken as anode.

A.

B.

C.

D.

The ores that are concentrated by floatation method are

• Carbonates

• Sulphides

• Oxides

• Phosphates

In blast furnance, iron oxide is reduced by

• Silica

• CO

• C

• Limestone

Which of the following metal is obtained by leaching its ore with dilute cyanide solution

• Silver

• Titanium

• Vanadium

• Zinc

Which method of purification is represented by the following equation?${\mathrm{T}}_{\mathrm{i}} + 2{\mathrm{I}}_2 \stackrel{\mathrm{\pi }3}{\to } {\mathrm{I}}_{\mathrm{i}} {\mathrm{I}}_4 \stackrel{1675\mathrm{K}}{\to } {\mathrm{T}}_{\mathrm{i}} + 2{\mathrm{I}}_2$

• Cupellation

• Polling

• Van Arkel

• Zone refining

Van Arkel method of purification of metals involves converting the metal to a

• volatile stable compound

• volatile unstable compound

• non-volatile stable compound

• None of the above