Blister copper is melted in a furnace then stirred with green wooden logs. The purpose is

• to expel the soluble gases out of the blister copper

• to bring the impurities on the surface to oxidise them

• to increase the carbon in copper

• to reduce the metallic oxide impurities by the hydrocarbon gases coming out of the log during the process

During smelting of an ore an additional substance is added to make the impurities fusible. The name of it is

• Slag

• mud

• gangue

• flux

In the metallurgy of which of the following cupellation process is used? 

• Copper

• Silver

• Iron

• Aluminium

Cryolite is used in the electrolytic extration of aluminium

• to obtain more aluminium

• to decompose bauxite

• to protect anodes

• as a reducing agent

The brass is an alloy of

• gold and copper

• silver and zinc

• copper and zinc

• copper and aluminum

In blast furnace, iron oxide is reduced by

• silica

• CO

• C

• limestone

In electrorefining of metal, the impure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of

• silver

• copper

• aluminium

• zinc

Match List I with List II and select the correct answer using the codes given below the lists.

• (P)	(Q)	(R)	(S)
  (3)	(2)	(4)	(1)

• (P)	(Q)	(R)	(S)
  (2)	(3)	(1)	(4)

• (P)	(Q)	(R)	(S)
  (4)	(1)	(2)	(3)

• (P)	(Q)	(R)	(S)
  (1)	(4)	(3)	(2)

Froth floatation process is used for the concentration of which one?

• Horn silver

• Haematite

• Bauxite

• Cinnabar

90.

A common metal used for the extraction of metals from their oxides by reduction is

• Al

• Fe

• Cr

• Co