Hydrocarbons CBSE Questions & Answers

Hydrocarbons

This is Chemistry Class 11 Hydrocarbons CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The synthesis of 3-octyne is achieved by adding a bromoalkane into a mixture of sodium amide and an alkyne. The bromoalkane and alkyne respectively are
  • A
    \({\text{BrC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{and C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C }} \equiv {\text{ CH}}\)
  • B
    \({\text{BrC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{and C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C }} \equiv {\text{ CH}}\)
    Correct
  • C
    \({\text{BrC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{and C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C }} \equiv {\text{ CH}}\)
  • D
    \({\text{BrC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{and C}}{{\text{H}}_{\text{3}}}{\text{C }} \equiv {\text{ CH}}\)
2
One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is
  • A
    2-butene
    Correct
  • B
    1-butene
  • C
    Ethane
  • D
    Propene
3
n-propyl bromide on treating with alcoholic KOH produces
  • A
    propanol
  • B
    propene
    Correct
  • C
    propane
  • D
    propyne
4
The angle strain in cyclobutane is
  • A
    \({\text{19}}^\circ {\text{22}}\prime \)
  • B
    \({\text{29}}^\circ {\text{16}}\prime \)
  • C
    \({\text{9}}^\circ {\text{44}}\prime \)
    Correct
  • D
    \({\text{24}}^\circ {\text{44}}\prime \)
5
In the following sequence of reactions, the alkene affords the compound 'B' \({\text{C}}{{\text{H}}_{\text{3}}}{\text{CH }} = {\text{ CHC}}{{\text{H}}_{\text{3}}}\mathop \to \limits^{{O_3}} {\text{A}}\mathop \to \limits^{{H_2}O,Zn} B\) The compound B is
  • A
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{CHO}}\)
  • B
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{COC}}{{\text{H}}_{\text{3}}}\)
  • C
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{COC}}{{\text{H}}_{\text{3}}}\)
  • D
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{CHO}}\)
    Correct
6
The hydrocarbon which can react with sodium in liquid ammonia is
  • A
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{CH}} = {\text{CHC}}{{\text{H}}_{\text{3}}}\)
  • B
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}} \equiv {\text{CC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}\)
  • C
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}} \equiv {\text{CH}}\)
    Correct
  • D
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}} \equiv {\text{CC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}\)
7
The treatment of \({\text{C}}{{\text{H}}_{\text{3}}}{\text{MgX with C}}{{\text{H}}_{\text{3}}}{\text{C }} \equiv {\text{ C}} - {\text{H}}\) produces
  • A
    Option A
  • B
    \({\text{C}}{{\text{H}}_{\text{4}}}\)
    Correct
  • C
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{C }} \equiv {\text{ C}} - {\text{C}}{{\text{H}}_{\text{3}}}\)
  • D
    \({\text{C}}{{\text{H}}_{\text{3}}} - {\text{CH }} = {\text{ C}}{{\text{H}}_{\text{2}}}\)
8
Benzene reacts with chlorine in sunlight to give a final product
  • A
    \({\text{CC}}{{\text{l}}_{\text{4}}}\)
  • B
    \({{\text{C}}_{\text{6}}}{\text{C}}{{\text{l}}_{\text{6}}}\)
  • C
    \({{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{Cl}}\)
  • D
    \({{\text{C}}_{\text{6}}}{{\text{H}}_{\text{6}}}{{\text{C}}_{{\text{l6}}}}\)
    Correct
9
The general formula of a cycloalkane is
  • A
    \({{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n}}}}\)
    Correct
  • B
    \({{\text{C}}_{\text{n}}}{\text{H}}{{\text{2}}_{{\text{n}}--{\text{2}}}}\)
  • C
    \({{\text{C}}_{\text{n}}}{\text{H}}{{\text{2}}_{{\text{n}} + {\text{2}}}}\)
  • D
    \({{\text{C}}_{\text{n}}}{{\text{H}}_{\text{n}}}\)
10
Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is
Question 10 figure 1
  • A
    (B)
  • B
    (A)
    Correct
  • C
    (D)
  • D
    (C)
11
The reagent(s) for the following conversion, is/are
Question 11 figure 1
  • A
    alcoholic KOH
  • B
    alcoholic KOH followed by \({\text{NaN}}{{\text{H}}_{\text{2}}}\)
    Correct
  • C
    aqueous KOH followed by \({\text{NaN}}{{\text{H}}_{\text{2}}}\)
  • D
    \({\text{Zn}}/{\text{C}}{{\text{H}}_{\text{3}}}{\text{OH}}\)
12
Presence of a nitro group in a benzene ring
  • A
    renders the ring basic
  • B
    activates the ring towards electrophilic substitution
  • C
    deactivates the ring towards nucleophilic substitution
  • D
    deactivates the ring towards electrophilic substitution
    Correct
13
The compound formed as a result of oxidation of ethyl benzene by \({\text{KMn}}{{\text{O}}_{\text{4}}}\) is
  • A
    benzoic acid
    Correct
  • B
    benzyl alcohol
  • C
    benzophenone
  • D
    acetophenone
14
Which of the following reactions will yield 2, 2-dibromopropane?
  • A
    \({\text{C}}{{\text{H}}_{\text{3}}} - {\text{ CH }} = {\text{ C}}{{\text{H}}_{\text{2}}} + {\text{ HBr }} \to \)
  • B
    \({\text{C}}{{\text{H}}_{\text{3}}} - {\text{ C }} \equiv {\text{ CH }} + {\text{ 2HBr }} \to \)
    Correct
  • C
    \({\text{CH }} \equiv {\text{ CH }} + {\text{ 2HBr}} \to \)
  • D
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{CH }} \equiv {\text{ CHBr }} + {\text{ HBr}} \to \)
15
HBr reacts with \({\text{C}}{{\text{H}}_{\text{2}}} = {\text{ CH }}--{\text{ OC}}{{\text{H}}_{\text{3}}}\) under anhydrous conditions at room temperature to give
  • A
    \({\text{BrC}}{{\text{H}}_{\text{2}}}{\text{CHO and C}}{{\text{H}}_{\text{3}}}{\text{OH}}\)
  • B
    \({\text{C}}{{\text{H}}_{\text{3}}}{\text{CHO and C}}{{\text{H}}_{\text{3}}}{\text{Br}}\)
  • C
    \({\text{BrC}}{{\text{H}}_{\text{2}}}--{\text{ C}}{{\text{H}}_{\text{2}}}--{\text{ OC}}{{\text{H}}_{\text{3}}}\)
  • D
    \({{\text{H}}_{\text{3}}}{\text{C }}--{\text{ CHBr }}--{\text{ OC}}{{\text{H}}_{\text{3}}}\)
    Correct