General Principles And Processes of Isolation Of Elements

Flux is used to 

• remove all type of impurities

• reduce metal oxide

• remove carbonate and sulphate

• remove silica and undesirable metal oxides

Lime stone is added in the extraction of lead from galena why?

• It prevents the formation of PbSO₄

• It remove the impurity of silica as fusible slag

• It converts lead silicate to lead oxide

• All of the above

The extraction of which of the following metals involves bessemerisation?

• Fe

• Ag

• Al

• Cu

Leaching is a process of

• reduction

• concentration

• refining

• oxidation

Common alum is

• K₂SO₄.Al₂(SO₄)₃.24H₂O

• (NH₄)₂SO₄.FeSO₄.6H₂O

• K₂SO₄.Cr₂(SO₄)₃.24H₂O

• K₂SO₄.Fe₂(SO₄)₃.24H₂O

Which of the following is not correct?

• Al reacts with NaOH and liberate H₂

• AlCl₃ is a Lewis acid

• Al is used in the manufacture of electrical cables

• NaOH is used during Hall's process of purification of bauxite

To dissolve argentite ore which of the following is used?

• Na[Ag(CN)₂]

• NaCN

• NaCl

• HCl

Which of the following statement is not correct?

• A furnace lined with haematite is used to convert cast iron to wrought iron

• Collectors enhance the muttability of mineral particles during froth floatation

• In vapour phase retining metal should form a volatile compound

• Copper from its low grades ores is extracted by hydrometallurgy

In the extraction of copper from its sulphide ore, the metal is formed by reduction of Cu₂O with:

• CO

• SO₂

• Cu₂S

• FeS

Bauxite is an ore of

• boron

• barium

• aluminium

• bismuth