Hydrocarbons MCQs – 3

1) In a mixture of n-hexadecane and -methylnaphthalene, if the percentage of n-hexadecane is 80, the cetane number of the fuel is :
a) 20
b) 100
c) 80
d) zero.

2) The raw material used in a Fishcer-Tropsch process for the manufacture of synthetic petroleum is
a) Water gas
b) Water gas + excess of hydrogen
c) Producer gas
d) Coal gas.

3) The Bergius process for the manufacture of synthetic petroleum involves
a) Hydrogenation of vegetable oils
b) Hydrogenation of coal
c) Dehydrogenation of alkenes
d) Hydrogenation of aromatic hydrocarbons.

4) Coal is a valuable source of
a) Inorganic compounds
b) Alicyclic compounds
c) Aromatic compounds
d) Aliphatic compounds.

5) Which of the following is not present in light oil?
a) Benzene
b) Toluene
c) Xylene
d) Naphthalene.

6) The main basic component present in coal-tar is
a) Pyridine
b) Cresols
c) Naphthalene
d) Toluene.

7) The main-constituent of the heavy oil fraction of coal tar distillation is
a) Naphthalene
b) Naphthols
c) Cresols
d) Anthracene.

8) Petrochemicals are obtained from
a) Coal-tar
b) Petroleum products
c) Coal
d) All the three

9) Petrochemicals can be used to prepare
a) Synthetic fibres alone
b) Pesticides alone
c) Plastics alone
d) All the three.

10) The approximate amount of benzene in “90% benzol” of coal tar origin is
a) 90
b) 70
c) 65
d) 50

11) The process used to remove carbon dioxide from carboxylic acids is called
a) Dehydrogenation
b) Decarboxylation
c) Carboxylation
d) Decarbonylation .

12) Soda-lime is a mixture of
c) NaOH + CaO

13) Soda-lime is a specific reagent for
a) Decarboxylation
b) Dehalogenation
c) Dehydration
d) Dehydrogenation.

14) What is X in the following sequence of reactions ?

a) Methanoic acid
b) Ethanoic acid
c) Propane
d) Methane.

15) The compound X produces methane when treated with water. The compound X is
a) Calcium carbide
b) Aluminium carbide
c) Calcium phosphide
d) Aluminium nitride.

16) The action of heavy water (D2O) on methyl magnesium bromide gives

17) The reaction:

2 R – X + 2 Na R-R + 2 NaX is an example of
b) Friedel-Crafts reaction
c) Wurtz reaction
d) Cannizzaro reaction.

18) Which of the following reactions can be used to prepare methane ?
a) Wurtz reaction
b) Decarboxylation of sodium acetate
d) Hydrogenation of alkenes.

19) Which of the following on treatment with zinc-copper-couple and ethanol will produce propane?
a) Propanal
b) Isopropyl bromide
c) Ispropylamine
d) Isopropyl alcohol.

20) When sodium propionate is heated with soda-lime, the product formed is
a) Methane
b) Ethane
c) Ethene
d) Ethyne.

21) Which of the following will not produce ethane ?
d) Hydrogenation of ethene in presence of Raney Ni.

22) The process of removing a molecule of halogen acid from an alkyl halide is called
a) Dehalogenation
b) Dehydrohalogenation
c) Halogenation
d) Hydrognation

23) When n-heptane is heated to about 773 K under high pressure in presence of Cr2O3 deposited over AI2O3, the final product formed is
a) Cyclohexane
b) Methylcyclohexane
c) Toluene
d) Benzene.

24) Which of the following compounds will form a hydrocarbon on reaction with a Grignard reagent ?

25) Methane is not formed when
a) Sodium acetate is heated with soda-lime
b) lodomethane is reduced
c) Aluminium carbide reacts with water
d) Formaldehyde is reduced with lithium aluminium hydride +

26) Coke is obtained by heating coal in the
a) Presence of air
b) Absence of air
c) Restricted supply of air
d) Presence of a catalyst.

27) The cetane number of a diesel fuel will increase with the addition of
a) n-Decane
b) n-Hexadecane
c) n-Pentane
d) Alpha-Methylnaphthalene.

28) The reagent is
a) Na
d) Hexane

29) A mixture of ethyl iodide and n-propyl iodide is subjected to the Wurtz reaction. The hydrocarbon which will not be formed is
a) Butane
b) Propane
c) Pentane
d) Hexane.

30) When petroleum is heated gradually, the first batch of vapours evolved will be rich in
a) Kerosene
b) Petroleum ether
c) Diesel
d) Lubricating oil.

31) Fractional distillation of coal-tar produces the following fractions. Phenol is the main component of which fraction ?
a) Light oil
b) Middle oil
c) Heavy oil
d) Green oil.

32) To prepare a pure sample of n-hexane using sodium metal as one reactant, the other reactant will be
a) Ethyl chloride and n-butyl chloride
b) Methyl bromide and n-pentyl bromide
c) n-Propyl bromide
d) Ethyl bromide and n-butyl bromide.

33) Which of the following is not a mixture of hydrocarbons ?
a) Candle wax
b) Kerosene
c) Vegetable oil
d) Paraffin oil.

34) In the reaction, C6H5CH3 the product C is

35) The reagent used for the conversion,

b) Soda-lime
c) Red P and concentrated HI
d) Amalgamated zinc and concentrated HCI.

36) Coal-tar is a main source of
a) Aromatic compounds
b) Aliphatic compounds
c) Cycloalkanes
d) Heterocyclic compounds.

37) Petrol used as a fuel in automobiles is a mixture of
a) Hydrocarbons
b) Alcohols
c) Carbohydrates
d) Hydrocarbons and alcohols

38) Which of the following liberates methane on treatment with water ?
a) Silicon carbide
b) Calcium carbide
c) Beryllium carbide
d) Magnesium carbide.

39) The Fischer-Tropsch process is used in the manufacture of
a) Synthetic petroleum
b) Ethanol
c) Benzene
d) Ethanoic acid.

40) Indicate the expected structure of the organic product when ethyl magnesium bromide is treated with heavy water (D2O)
c) Sodium benzoate

41) n-Propyl bromide on heating with ethanolic potassium hydroxide produces mainly
a) Propanol-1
b) Propene
c) Propanol-2
d) Ethyl propyl ether.

42) The electrolysis of cold concentrated aqueous solution of potassium succinate yields
a) Ethane
b) Ethyne
c) Ethene
d) Ethane-1, 2-diol.

43) Petrol for aviation purposes must contain mainly
a) Straight chain hydrocarbons
b) Aromatic hydrocarbons
c) Olefinic hydrocarbons
d) Highly branched chain paraffins

44) A liquid hydrocarbon is converted into a mixture of gaseous hydrocarbons by
a) Cracking
b) Hydrolysis
c) Oxidation
d) Reduction.

45) The formation of alkanes by the action of Zn on alkyl halides is called the
a) Frankland reaction
b) Cannizzaro reaction
c) Wurtz reaction

46) Monosodium acetylide reacts with an alkylhalide to form
a) An alkane
b) An alkene
c) An unsymmetric higher alkyne
d) A symmetric higher alkyne.

47) In an industrial process, coke is heated with quicklime in an electric furnace and the cooled product is then treated with water to produce
a) Acetylene
b) Ethylene
c) Ethane
d) Methane.

48) Crude naphtha is a mixture of
a) Alkanes
b) Conjugated dienes
c) Alkynes
d) Alkyl halides

49) Tetraethyl-lead is a
a) Solvent
b) Petroleum additive
c) Oxidising agent
d) Fire extinguisher.

50) When an alkyl iodide (Rl) is treated with Na in dry ether, a symmetrical alkane (R2) is obtained. The reaction is called
a) Grignard reaction
b) Fischer-Tropsch reaction
c) Berguis reaction
d) Wurtz reaction.

51) When n-propyl iodide is heated with alcoholic KOH, one of the products is

52) Which of the following is used as an antiknocking material ?
a) T.E.L.
c) Glycoxal
d) Freon.

53) Which of the following isomers will have the highest octane number ?
a) n-octane
b) 2-Methylheptane
c) 2, 3-Dimethylhexane
d) 2, 2, 4-Trimethylpentane.

54) In commercial gasoline, the types of hydrocarbons which are desirable are
a) Branched hydrocarbons
b) Straight chain hydrocarbons
c) Linear unsaturated hydrocarbons
d) Toluene

55) (CH3)3CMgCI on reaction with D2O produces

56) The purest(most evolved) form of coal is
a) Peat
b) Anthracite
c) Lignite
d) Bituminous.

57) Benzene is obtained by fractional distillation of … from coaltar.
a) Light oil
b) Middle oil
c) Anthracene oil
d) Heavy oil.

58) In the Wurtz reaction, the reagent used is
a) Na
c) Na/dry ether
d) Na/dry alcohol.

59) 1-Chlorobutane, on reaction with hot alcoholic potash (KOH), gives mainly
a) 1-Butene
b) 1-Butanol
c) 2-Butene
d) 2-Butanol.

60) Ethyl bromide on heating with alcoholic KOH gives mainly
a) Ethylene
b) Ethanol
c) Acetic acid
d) Ethane

61) For preparing an alkane, a concentrated solution of the sodium or potassium salt of a saturated carboxylic acid is subjected to
a) hydrolysis
b) oxidation
c) hydrogenation
d) electrolysis

62) The octane number is zero for
a) n-Heptane
b) Isooctane
c) n-Hexane
d) Isoheptane

63) Heating a mixture of sodium benzoate or benzoic acid and soda-lime gives
a) Benzene
b) Methane
c) Sodium benzoate
d) Calcium benzoate

64) Which of the following has the highest octane number ?
a) n-Hexane
b) n-Heptane
c) n-Pentane
d) 2,2,4-Trimethylpentane

65) Which one is used as an antiknock in petrol fuel?
a) Basic lead carbonate
b) Lead tetraacetate
c) Tetraethyl-lead
d) Basic lead sulphate

66) Tetrabromoethane on heating with Zn gives
a) Ethyl bromide
b) Ethane
c) Ethene
d) Ethyne

67) Both methane and ethane can be prepared in one step, but through different reactions, from

68) Both ethylene and acetylene can be prepared in one step, but by different reactions, from

69) When bromoethane is subjected to the Wurtz reaction, the hydrocarbon mixture so obtained consists of
a) Butane only
b) Butane and ethane only
c) Butane and ethene only
d) Butane, ethane and ethene.

70) Select the major product formed from the treatment of 2- bromobutane and alcoholic KOH.

71) 1, 3-Dichloropropane reacts with zinc and Nal and gives (major product)
a) Propane
b) Propene
c) Cyclopropane
d) n-Proploidide

72) The number of carbon atoms in paraffin oil (kerosene) is
a) 1-5
b) 5-10
c) 12-15
d) 16-20.

73) The reaction of sodium formate with soda-lime gives
a) Methane
b) Hydrogen
c) Ethane
d) None of these.

74) In an attempt to prepare propane by the Wurtz reaction, 1 mole of methyl bromide and 1 mole of ethyl bromide are treated with sodium. Assuming equal probability for all possible reactions, how many grams of propane will be obtained ?
a) 44g
b) 22g
c) 33 g
d) None of the above.

75) The number of alkanes obtained on electrolysis of a mixture of CH3COONa and C2H5COONa are
a) 1
b) 2
c) 3
d) 4.

76) @ The compound which produces propene on heating with alcoholic potash is
d) None of the above

77) @ The best reagent to convert 1, 2-dichloropropane to propyne is
a) Zinc dust
c) aqueous alkali
d) iodide ion

78) The olefinic double bond is easily reduced by
a) Hydrogen gas
b) Metal and acid
c) Sodium and ethanol
d) Hydrogen and nickel.

79) During the preparation of alkanes by Kolbes electrolytic method using inert electrodes, the pH of the electrolyte
a) decreases progressively as the reaction proceeds
b) increases progressively as the reaction proceeds
c) remains constant throughout the reaction
d) may decrease if the concentration of the electrolyte is not very high.

80) Dehydrohalogenation of neopentyl chloride with alcoholic

    mainly gives

a) 2-Methyl-1-butene
b) 2-Methyl-2-butene
c) 2, 2-Dimethyl-1-butene
d) 2-Butene.

81) Which of the following reactions gives

82) Aqueous solutions of the following compounds are electrolysed. Acetylene gas is obtained from
a) Sodium fumarate
b) Sodium succinate
c) Sodium acetate
d) Both a and b.

83) Which of the following fractions of coal-tar distillation does not contain naphthalene ?
a) Light oil
b) Middle oil
c) Heavy oil
d) Both b and c

84) Reforming is not used to
a) increase the octane number
b) prepare straight chain alkanes
c) prepare aromatic hydrocarbons
d) To obtain value added products

85) Toluene can be prepared by
a) Heating p-toluic acid with soda-lime
b) Benzyl alcohol with Zn amalgam and HCl
c) Reacting phenol with methyl iodide and abhydrous AlCl 3
d) All of the above

86) Benzene is obtained when
b) Ethene is passed through red hot iron tube
c) Benzenesulphonic acid is treated with sulphuric acid
d) All the above

87) Which of the following alcohols on dehydration with conc. at 440 K will not give propene ?
a) Isobutyl alcohol
b) n-Propyl alcohol
c) Isopropyl alcohol
d) Both b and c

88) Solid methane is
a) A molecular solid
b) An ionic acid
c) A covalent solid
d) Does not exist

89) Which of the following can show geometrical isomerism ?
a) 2-Butene
b) Isobutane
c) 1, 3-Butadiene
d) Both(a) and (c)

90) Which of the following alkanes has the lowest boiling point ?
a) n-Pentane
b) Isopentane
c) Neopentane
d) n-Hexane.

91) Which of the following alkanes has the lowest melting point ?
a) n-Butane
b) n-Pentane
c) Propane
d) n-Hexane.

92) Which of the following hydrocarbons has the highest melting point ?
a) o-Xylene
b) p-Xylene
c) m-Xylene
d) Toluene.

93) 20 ml of methane are burnt with 50 ml of oxygen, the volume of the gas left after cooling to room temperature will be
a) 80 ml
b) 60 ml
c) 30ml
d) 20ml.

94) 10 ml of a gaseous hydrocarbon requires 30 ml of oxygen for complete combustion. The hydrocarbon is

95) Assuming petrol is isooctane (C8H18) and has a density of 0.8 g ml-1, 1.425 litres of petrol on complete combustion will consume

96) Halogenation of alkanes is an example of
a) Free radical addition reaction
b) Free radical substitution reaction
c) Nucleophilic substitution reaction
d) Nucleophilic addition reaction.

97) The order of abstraction of primary, secondary and tertiary hydrogen atoms in alkanes by a halogen atom follows the sequence

98) The maximum ease of abstraction of a hydrogen atom by a chlorine atom is shown by

99) The order of reactivity of different halogens towards halogenation of alkanes follows the sequence

100) Which of the following is the correct sequence of steps in a chain reaction ?
a) Propagation, initiation, termination
b) Initiation, termination, propagation
c) Propagation, termination, initiation
d) Initiation, propagation, termination.


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