Free NCERT Solutions For Class 11 Chemistry Chapter 13 : Hydrocarbons Free PDF Download

Question 1:
How do you account for the formation of ethane during chlorination of methane?

Question 2:
Write IUPAC names of the following compounds:

Question 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)

Question 4:
Write IUPAC names of the products obtained by the ozonolysis of the followingcompounds:
(i) Pent-2-ene
(ii) 3,4-Dimethyl-hept-3-ene
(iii) 2-Ethylbut-1-ene
(iv) 1-Phenylbut-1-ene

Solution 4:
(i) Pent-2-ene undergoes ozonolysis as:

Question 5:
An alkene ‘A’ on ozonolysis gives a mixture of ethanal and pentan-3-one. Write structure and IUPAC name of ‘A’.

Question 6:
An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C π bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.

Question 7:
Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?

Question 8:
Write chemical equations for combustion reaction of the following hydrocarbons:
(i) Butane
(ii) Pentene
(iii) Hexyne
(iv) Toluene

Question 9:
Draw the cis and trans structures of hex-2-ene. Which isomer will have higher b.p. and why?

Question 10:
Why is benzene extra ordinarily stable though it contains three double bonds?

Question 11:
What are the necessary conditions for any system to be aromatic?

Question 12:
Explain why the following systems are not aromatic?
(i)

Question 13:
How will you convert benzene into
(i) p-nitrobromobenzene
(ii) m-nitrochlorobenzene
(iii) p -nitrotoluene
(iv) acetophenone

Question 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 15:
What effect does branching of an alkane chain has on its boiling point?

Question 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.

Question 17:
Write down the products of ozonolysis of 1, 2-dimethylbenzene (o-xylene). How does the result support Kekule structure for benzene?

Question 18:
Arrange benzene, n-hexane and ethyne in decreasing order of acidic behaviour. Also give reason for this behaviour.

Question 19:
Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Question 20:
How would you convert the following compounds into benzene?
(i) Ethyne
(ii) Ethene
(iii) Hexane

Question 21:
Write structures of all the alkenes which on hydrogenation give 2-methylbutane.

Question 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.

Question 23:
Out of benzene, m–dinitrobenzene and toluene which will undergo nitration most easily and
why?

Question 24:
Suggest the name of a Lewis acid other than anhydrous aluminium chloride which can be used
during ethylation of benzene.

Question 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.