Metallurgy step 3 Learner level

Poling is used for

• for the removal of Cu2O from Cu

• For the removal of Al2O3 from Al

• for the removal of Fe2O3 from Fe

• in all of these

the purest form of commercial iron is

• Pig iron

• cast iron

• wrought iron

• pig iron and cast iron

In the commercial electrochemical process for aluminium extraction, the electrolyte used is

• Al(OH)3 in NaOH solution

• An aqueous solution of Al2(SO4)3

• A molten mixture of Al2O3 and Na3AlF6

• A molten mixture of AlO(OH) and Al(OH)3

Electrolytic refining is used in the extraction of

• Aluminium

• Iron

• Copper

• Both A and C

In electrorefining of metals, the anode is made of

• the impure metal concerned

• The pure metal concerned

• graphite

• silica

For vapour phase refining process select the correct statements

• The impure metal is converted into its volatile compound

• The volatile compound should be decomposed to pure metal on heating

• Van-Arkel process is an example of vapour phase refining method

• Ni is purified by vapour phase refining process

The metal refined by liquation process is

• Sn

• Pb

• Zn

• Hg

In electro refining of metal the impure metal is made as anode and strip of pure metal as cathode during the electrolysis of an aqueous solution of a complex metal salt. This method can be used for refining of

• Silver

• Copper

• Nickel

• Gold

In zone refining process when moving circular health is used how many zones are formed on impure metal

• 1

• 2

• 3

• 4

Total number of atoms present in Nickel carbonyl

• 3

• 5

• 7

• 9