EXERCISES

Question 13.10:- 

Why is benzene extraordinarily stable though it contains three double bonds?

Question 13.11:-

What are the necessary conditions for any system to be aromatic?

Question 13.12:-

Explain why the following systems are not aromatic?

(i)

(ii)

(iii)

Question 13.13:- 

How will you convert benzene into

(i) p-nitrobromobenzene

(ii) m- nitrochlorobenzene

(iii) p - nitrotoluene

(iv) acetophenone?

Question 13.14:-

In the alkane H3C – CH2 – C(CH3)2 – CH2 – CH(CH3)2, identify 1°,2°,3° carbon atoms, and give the number of H atoms bonded to each one of these.

Question 13.15:- 

What effect does branching of an alkane chain has on its boiling point?

Question 13.16:-

Addition of HBr to propene yields 2-bromopropane, while in the presence of benzoyl peroxide, the same reaction yields 1-bromopropane. Explain and give mechanisms.

13.17 Write down the products of ozonolysis of 1,2-dimethyl benzene (o-xylene). How does the result support the Kekulé structure for benzene?

Question13.18:- 

Arrange benzene, n-hexane and ethyne in decreasing order of acidic behaviour. Also, give a reason for this behaviour.

Question 13.19:-

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Question 13.20:-

How would you convert the following compounds into benzene?

(i) Ethyne

(ii) Ethene

(iii) Hexane