Chemistry Of Group IV Elements

Question 1

Where are carbon and silicon found?

Answer 1

In the Earth’s crust.

Question 2

In what form do tin and lead occur in nature?

Answer 2

As Cassiterite (SnO2) and Gelena (PbS).

Question 3

How is silicon different from carbon in terms of occurrence?

Answer 3

Silicon does not exist freely in nature; it is wildly obtained as silica (SiO2) and silicate materials (alumminosilicate)

Question 4

How is carbon black obtained?

Answer 4

Carbon black can be obtained by burning petroleum hydrocarbon in limited air

Question 5

How are silicon, tin, and germanium obtained?

Answer 5

They are obtained by reducing their oxides. Carbon is the reducing agent.

SiO2 + 2C —> Si + 2CO

Question 6

How is lead obtained?

Answer 6

Lead is obtained by roasting Galena (PbS) in air to give lead oxide.

2PbS + 3O2 → 2PbO + 2SO2

2PbO + C → 2Pb + CO2

Question 7

What is allotropy?

Answer 7

Allotropy is the occurrence of an element in different forms but the same physical state.

Question 8

What are the crystal and amorphous allotropes of carbon?

Answer 8

Crystal: diamond and graphite

Amorphous: carbon black, coal, charcoal