The purest form of iron is-

1. Cast iron

2. Steel

3. Wrought iron

4. Grey cast iron

Out of following which metal can be purified by Van Arkel method?

Bauxite, an ore of aluminium is purified by

1. Hall's process

2. Serpeck's process

3. Bayer's process

4. All of the above

Which is mismatched?

1. Zincite - ZnO

2. Calamine - $ZnC{O}_3$

3. Siderite - $FeC{O}_3$

4. Malachite - $CuC{O}_3$

The ore having two different metal atoms is

1. Haematite

2. Galena

3. Magnetite

4. Copper pyrites

Which of the following is not a carbonate ore?

1. Siderite

2. Zincite

3. Calamine

4. Dolomite

Which of the following is not an ore of silver?

1. Pyrargyrite

2. Argentite

3. Anglesite

4. All of the above

For which of the following metals, distillation method is used for purification ?

1. Zn

2. Cd

3. Hg

4. All of the above

Magnesium oxide is used for the lining in steel making furnance because

1. It is reduced to Mg metal easily

2. It acts as a flux

3. It increases oxidizing power of steel

4. All of the above

Carbon cannot be used in the reduction of $A{l}_2{O}_3$ because

1. The enthalpy of formation of $C{O}_2$ is more than that of $A{l}_2{O}_3$

2. Pure carbon is not easily available

3. The enthalpy of formation of $A{l}_2{O}_3$ is very high

4. It is an expensive process