Write three common functional groups present in organic compounds. Give their symbols/formulae.

38 What is meant by ‘heteroatom’? Give examples. Write the names and formulae of two organic compounds containing different heteroatoms. 39 What is meant by a functional group? Explain with an example. 39 Name the functional groups present in the following compounds:

(i) CH₃COOH (ii)CH₃CH₂CH₂CHO (iii) C₂H₅OH (iv) CH₃COCH₂CH₃

39 Name the functional group which always occurs in the middle of a carbon chain.