EXERCISES
13.1 How do you account for the formation of ethane during chlorination of methane ?
13.1 How do you account for the formation of ethane during chlorination of methane ?
13.2 Write IUPAC names of the following compounds :
(a) CH3CH=C(CH3)2 (b) CH2=CH-C≡C-CH3
(c) (d) –CH2–CH2–CH=CH2
(e)
−
3 24 23 3
2 32
(f ) CH (CH ) CH(CH ) CH
|
CH CH(CH )
(g) CH3 – CH = CH – CH2 – CH = CH – CH – CH2 – CH = CH2
|
C2H5
13.3 For the following compounds, write structural formulas and
IUPAC names for all
possible isomers having the number of double or triple bond as
indicated :
(a) C4H8 (one double bond) (b) C5H8 (one triple bond)
13.4 Write IUPAC names of the products obtained by the
ozonolysis of the following
compounds :
(i) Pent-2-ene (ii) 3,4-Dimethyl-hept-3-ene
(iii) 2-Ethylbut-1-ene (iv) 1-Phenylbut-1-ene
13.5 An alkene ‘A’ on ozonolysis gives a mixture of ethanal and
pentan-3-
one. Write structure and IUPAC name of ‘A’.
13.6 An alkene ‘A’ contains three C – C, eight C – H ó bonds and one C – C
ð bond. ‘A’ on ozonolysis gives two moles of an
aldehyde of molar mass
44 u. Write IUPAC name of ‘A’.
13.7 Propanal and pentan-3-one are the ozonolysis products of an
alkene?
What is the structural formula of the alkene?
13.8 Write chemical equations for combustion reaction of the
following
hydrocarbons:
(i) Butane (ii) Pentene
(iii) Hexyne (iv) Toluene
13.9 Draw the cis and trans structures of hex-2-ene. Which isomer will have
higher b.p. and why?
13.10 Why is benzene extra ordinarily stable though it contains
three double
bonds?
13.11 What are the necessary conditions for any system to be
aromatic?
13.12 Explain why the following systems are not aromatic?
(i) (ii) (iii)
13.13 How will you convert benzene into
(i) p-nitrobromobenzene (ii) m- nitrochlorobenzene
(iii) p - nitrotoluene (iv) acetophenone?
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.
13.15 What effect does branching of an alkane chain has on its
boiling point?
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 mechanism.
13.17 Write down the products of ozonolysis of
1,2-dimethylbenzene (o-xylene).
How does the result support Kekulé structure for benzene?
13.18 Arrange benzene, n-hexane and ethyne in
decreasing order of acidic
behaviour. Also give reason for this behaviour.
13.19 Why does benzene undergo electrophilic substitution
reactions easily
and nucleophilic substitutions with difficulty?
13.20 How would you convert the following compounds into
benzene?
(i) Ethyne (ii) Ethene (iii) Hexane
13.21 Write structures of all the alkenes which on hydrogenation
give
2-methylbutane.
13.22 Arrange the following set of compounds in order of their
decreasing
relative reactivity with an electrophile, E+
(a) Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene
(b) Toluene, p-H3C – C6H4 – NO2, p-O2N – C6H4 – NO2.
13.23 Out of benzene, m–dinitrobenzene and toluene
which will undergo
nitration most easily and why?
13.24 Suggest the name of a Lewis acid other than anhydrous
aluminium
chloride which can be used during ethylation of benzene.
13.25 Why is Wurtz reaction not preferred for the preparation of
alkanes
containing odd number of carbon atoms? Illustrate your answer by
taking
one example.