Page 196 - ICSE Chemistry 8

Acids
Ethanoic acid CH COOH
3
Oxalic acid (COOH) 2
Sugar
Glucose C H O 6
6
12
The reason for the presence of such a large number of carbon compounds is its valency. Carbon has
atomic number 6. Its electronic confi gura on is (2, 4). The valency of carbon is 4 due to which it can form
covalent bonds with a number of carbon atoms as well as other atoms like hydrogen, oxygen, nitrogen,
sulphur and chlorine.

Some Useful Carbon Products

• Polyvinyl chloride (PVC) is used for making pipes.
Covalent Bond
• Bakelite is a sturdy plas c having high resistance. It can be
A bond formed by sharing of
moulded into diff erent shapes. Bakelite is an insulator and is used
electrons is called covalent
to make electrical switches and handles of various utensils. It is bond.
also used to make telephones, cameras, etc.
• Polythene is the most common carbon product used. It is mostly used to make carry bags, pipes,
household ar cles, etc.

Activity 9.1

Aim: To show the presence of carbon in sugar
Materials required: Some sugar, a test tube, a burner
Procedure

Take some sugar in a test tube and heat it for some me.
Observa on: The sugar melts and then turns brown. It fi nally
gets charred and turns black. sugar

Conclusion: This black substance observed is carbon.
burner
This proves that sugar contains carbon.
Similarly, if you burn coal, wood, paper, etc. you will no ce that a
black residue is formed a er burning. The black residue formed
consists of carbon.

CHEMICAL PROPERTIES OF CARBON

• Carbon is insoluble in all solvents.

• When carbon is heated with excess supply of oxygen, it forms carbon dioxide. This is because it has
a great affi nity for oxygen.
C + O 2 CO  + Heat
2
Carbon Excess oxygen Carbon dioxide

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