Corundum is ...... mineral of aluminium.

• Silicate

• Oxide

• Double salt

• Sulphate

Match the following-

• A - r; B - p; C - t; D - q; E - s

• A - t; B - s; C - q; D - p; E - r

• A - t; B - r; C - q; D - p; E - s

• A - t; B - s; C - q; D - r; E - p

43.

In the metallurgy of zinc; the reducing agent employed in reducing the zinc oxide to crude zinc metal in the last stage is

• Al

• Li

• Coke

• Water gas

Which metal is refined by Mond's process?

• Titanium

• Copper

• Nickel

• Zinc

According to Ellingham diagram, the oxidation reaction of carbon to carbon monoxide may be used to reduce which one of the following oxides at the lowest temperature?

• Al₂O₃

• Cu₂O

• MgO

• ZnO

The elements present in the core of earth are collectively known as

• lithophiles

• nucleophiles

• chalcophiles

• siderophiles

Vapour phase refining of nickel is carried out using:

• I₂

• Cl₂

• HCl

• CO

The froth-floatation process is based upon:

• he difference in the specific gravity of ore and gangue particles

• the magnetic properties of gangue and ore

• preferential wetting of gangue particles by oil

• preferential wetting of ore particles by oil

A certain metal will liberate hydrogen from dilute acids. It will react with water to form hydrogen only when the metal is heated and the water is in the form of steam. The metal is probably:

• iron

• potassium

• copper

• mercury

Name of the alloy of aluminium which is used in aeroplane is :

• duralumin

• bell metal

• aluminium bronze

• alumina