PURIFICATION AND CHARACTERISATION OF ORGANIC COMPOUNDS – 1

1) The empirical formula of a compound is . Its vapour density is 30. It does not react with sodium metal. The compound is
a) HCHO
b)
c)
d) none of these

2) The huge number of organic compounds is due to the fact that
a) carbon is tetravalent
b) carbon possesses the property of catenation
c) carbon compounds exhibit isomerism(
d) Both (b) and (c).

3) What is the nature of linkage in organic compounds? or ,Organic compounds may contain which type of bond(s)?
a) Ionic only
b) Covalent only
c) Co-ordinate covalent only
d) All the above

4) Which of the following properties is not true regarding organic compounds ?
a) They are generally covalent compounds
b) They have high melting and boiling points
c) They are generally insoluble in water
d) They generaly show isomerism

5) Which of the following groups contains a co-ordinate covalent bond ?
a) CN
b) NO
c)
d) None of the above

6) An example of an alicyclic compound is
a) Benzene
b) Hexane
c) Cyclohexane
d) Furan

7) Which of the following is an aromatic compound ?
a) Terahydrofuran
b) Anthracene
c) Piperidine
d) All are aromatic

8) Which of the following is not a carbocyclic compound ?
a) Cyclopentane
b) Naphthalene
c) Thiophene
d) Benzene

9) “Absolute alcohol”(99.5%) can be prepared from rectified spirit by
a) azeotropic distillation with benzene
b) fractional distillation
c) keeping the latter over fresh MgSO4 for a few hours and then distilling
d) By keeping the latter over anhydrous calcium chloride and then distilling

10) The Kjeldhal method is used to estimate the following elements in an organic compound?
a) C and N
b) S alone
c) N alone
d) S and N

11) Anthracene can be purified by
a) Filtration
b) Electrophoresis
c) Distillation
d) Sublimation

12) In Dumas method, the gas which is collected in the nitrometer is
a)
b) NO
c)
d)

13) Which of the following is an aromatic heterocyclic compound ?
a) Pyrrole
b) Pyrrolidine
c) Ethylene oxide
d) Dioxane

14) Which of the following is/are alicyclic heterocyclic compounds ?
a) Tetrahydrofuran
b) Pyrrole
c) Thiophene
d) All

15) Which of the following does not contain fused benzene rings ?
a) Naphthalene
b) Anthracene
c) Diphenyl
d)

16) Separation of two substances by fractional crystallisation depends upon their difference in
a) Densities
b) Solubilities
c) Melting point
d) Boiling points

17) Sugar containing an impurity of common salt can be purified by crystallization from
a) Benzene
b) Alcohol
c) Petroleum ether
d) None of the above

18) A mixture of benzoic acid and naphthalene can be separated by crystallization using hot water because
a) Benzoic acid is more soluble than naphthalene in hot water
b) Benzoic acid is less soluble than naphthalene in hot water
c) Both are insoluble in hot water
d) None of the above

19) When a solid vaporises directly without melting, the process is called
a) Evaporation
b) Sedimentation
c) Sublimation
d) Saponification

20) Naphthalene can be purified by
a) Sublimation
b) Extraction with alkali followed by reprecipitation
c) Extraction with acid followed by reprecipitation
d) None of the above

21) Sublimation cannot be used for purification of
a) Naphthalene
b) Camphor
c) Benzoic acid
d) Urea

22) The boiling point of which of the following is influenced by intermolecular hydrogen bonding ?
a) Ethanol
b) acetic acid
c) Acetone
d) Benzene

23) By decreasing the pressure, the boiling point of a liquid
a) Increases
b) Decreases
c) Remains constant
d) May increase or decrease

24) One of the earliest classes of compounds separated by chromatography is:
a) Petroleum components
b) Insecticide residues in food
c) Sugars
d) Plant pigments

25) @ Vaccum distillation is used for purification of a liquid when it is
a) Poorly volatile
b) Highly volatile
c) Not avaible in large quantities
d) None of the above

26) A mixture of acetone and methanol can be separated by
a) Vacuum distillation
b) Steam distillation
c) Fractional distillation
d) solvent extraction

27) The refining of petroleum involves the process of
a) Simple distillation
b) Fractional distillation
c) Steam distillation
d) None of the above

28) A substance which decomposes at or below its boiling point can be purified by
a) Simple distillation at atmospheric pressure
b) Fractional distillation at atmospheric pressure
c) Distillation in an inert atmosphere
d) Distillation under reduced pressure

29) Aniline is insoluble in water and possesses a vapour pressure of 10-15 mm Hg at 373 K. It can be conveniently purified by
a) Sublimation
b) Crystallization
c) Steam distillation
d) None of the above

30) In steam distillation, the sum of the vapour pressure of the volatile compound and that of water is
a) Equal to atmospheric pressure
b) Less than atmospheric pressure
c) More than atmospheric pressure
d) Exactly half of the atmospheric pressure

31) A mixture of o-hydroxyacetophenone and p-hydroxyacetophenone can be separated by
a) Sublimation
b) Steam distillation
c) electrophoresis
d) Distillation

32) Which among the following can be purified by steam distillation?
a) Resorcinol
b) Aniline
c) Benzoic acid
d) p-Nitrophenol

33) Steam distillation is used for the extraction of
a) Essential oils
b) Higher alkynes
c) Minerals oils
d) Fatty acids

34) An organic compound from its aqueous solution can be separated by
a) Distillation
b) Steam distillation
c) Solvent extraction
d) Fractional distillation

35) Chromatographic technique was introduced by
a) Duma (1803)
b) Kjeldahl (1903)
c) Tswett (1906)
d) None of the above

36) The separation of the constituents of a mixture by column chromatography depends upon their
a) Different solubilities
b) Different boiling points
c) Different refractive indices
d) Differential adsorption

37) In paper chromatography
a) The mobile phase is a liquid and the stationary phase is a solid
b) The mobile phase is a solid and the stationary phase is a liquid
c) Both phases are liquids
d) Both phases are solids

38) The technique of gas chromatography is suitable for compounds which
a) are liquids
b) are highly volatile
c) are soluble in water
d) Vapourize without decomposition

39) A mixture of camphor and benzoic acid can be separated by
a) Chemical method
b) Gel filtration
c) Fractional distillation
d) Ultra centrifugation

40) Distillation under reduced pressure is employed for
a) Benzene
b) Gasoline
c) Glycerol
d) Gegetable oils and fats

41) The most satisfactory method to separate sugars is to use
a) Fractional crystallization
b) Sublimation
c) Chromatography
d)

42) Sublimation cannot be used for the purification of
a) Glucose
b) Camphor
c) Benzoic acid
d) Naphthalene

43) Thiophene can be removed from commercial benzene by
a)
b)
c) Steam distillation
d) Fractional distillation

44) Which of the following will dissolve in dilute alkali ?
a) Salicylaldehyde
b) Bromobenzene
c) Nitrobenzene
d) All the above

45) In petroleum refining , which fraction is obtained by vacuum distillation ?
a) Ligroin
b) Gasoline
c) Kerosene
d) Lube oil

46) A simple method to establish that two solid organic compounds are identical is
a) determining their melting points
b) determining their mixed melting point
c) Microscopic examination
d) Colour, density, odour etc

47) In Lassaignes test, the organic compound is fused with a piece of sodium metal in order to
a) Increase the ionization of the compound
b) Decrease the melting point of the compound
c) Increase the reactivity of the compound
d) Convert the covalent compound into a mixture of ionic compounds

48) Which of the following compounds may give a blood red colouration while performing Lassaignes test for nitrogen ?
a)
b) Ethylene diamine
c) p-Nitroaniline
d) Thiourea

49) Concentrated nitric acid is added to Lassaignes extract during the detection of halogens to
a) Increase the concentration of nitrate ions
b) Increase the solubility product of AgCl
c) Help in the precipitation of AgCl
d)

50) In the Lassaignes test for the detection of nitrogen in an organic compound, the blue or green colour is due to the formation of
a)
b)
c)
d)

51) In the Lassaignes test, the blood red colouration is due to the formation of
a)
b) NaCNS
c)
d)

52) The formation of violet colour when sodium nitroprusside is added to sodium extract indicates the presence of
a) Nitrogen
b) Sulphur
c) Oxygen
d) Halogens

53) A violet colour with sodium nitroprusside in the test of sulphur in an organic compound is due to the formation of
a)
b)
c)
d)

54) For detection of sulphur in an organic compound, the Lassaignes extract is acidified with dilute acetic acid and lead acetate is then added to it. The black precipitate obtained is due to the formation of
a) PbS
b)
c)
d) None of these

55) A compound which does not give a positive result in the Lassaignes test for nitrogen is
a) Urea
b) Hydrazine
c) Glycine
d) Phenylhydrazine

56) Which of the elements N,S, or halogen in an organic compound can be detected by Lassaignes test?
a) N only
b) S and N only
c) Cl and N only
d) All the above three

57) When an organic compound containing phosphorus is fused with the fusion mixture, it gives
a)
b)
c)
d)

58) For the detection of phosphorus, the organic compound after fusion with is extracted with water, boiled with and then ammonium molybdate added to it. A yellow ppt. is obtained which is due to the formation of
a) Ammonium phosphate
b) Ammonium phosphomolybdate
c) Ferric phosphate
d) Disodium ammonium phosphate

59) The presence of carbon in a compound is detected by heating it with
a) Sodium metal to convert it into NaCN
b) CaO to convert it into CO which burns with a blue flame
c)
d) Cu wire to give a bluish-green flame

60) The water formed during detection of hydrogen is passed over
a)
b)
c)
d)

61) The copper wire test for halogens is known as
a)
b)
c)
d)

62) Beilsteins test is a rapid test used for organic compounds to detect
a) Phosphorus
b) Sulphur
c) Halogens
d) Nitrogen

63) Which of the following statements is not applicable to Beilsten’s test?
a) A green or bluish-green flame is due to the formation of volatile cupric halides
b) It does not tell as to which halogen (Cl.Br or I) is actually present in the organic compound
c) It is a very sensitive test and can be easily performed
d) It is a sure test for the presence of halogens

64) Amongst the following elements present in an organic compound, the one which has no direct test for detection is
a) Cl
b) N
c) S
d) O

65) Kjeldahls method can be used for the estimation of nitrogen in
a) Pyridine
b) Nitro compounds
c) Aniline
d) All the three above

66) Which of the following methods is used to estimate nitrogen in the laboratory?
a)
b)
c)
d) Carius method

67) In organic compounds, sulphur is estimated as
a)
b)
c)
d)

68) In organic compounds, phosphorus is estimated as
a)
b)
c)
d)

69) The percentage of hydrogen is maximum in
a)
b)
c)
d)

70) The percentage of carbon in acetic acid is
a) 40
b) 33.3
c) 50
d) 20

71) 0.2 g of an organic compound on Kjeldahls analysis gave enough ammonia to just neutralize of 0.1 N . The percentage of nitrogen in the compound is
a) 14
b) 28
c) 42
d) 4.2

72) 0.28 g of a nitrogenous compound was Kjeldahlised to produce 0.17 g of . The percentage of nitrogen in the organic compound is
a) 5
b) 30
c) 50
d) 80

73) Kjeldahls method is used in the estimation of
a) Nitrogen
b) Halogens
c) Sulphur
d) Oxygen

74) If 0.2 g of an organic compound on complete combustion produces 0.44 g of , then the percentage of carbon in it is
a) 50
b) 60
c) 70
d) 80

75) In the sodium test of organic compounds, the nitrogen of the organic compound is converted into
a) Sodamide
b) Sodium cyanide
c) Sodium nitrite
d) Sodium nitrate

76) A gaseous hydrocarbon has 85 % carbon and a vapour density of 28. The possible formula of the hydrocarbon will be
a)
b)
c)
d)

77) Two elements X (atomic weight = 75) and Y (atomic weight = 16) combine to give a compound having 75.8 % X. The formula of the compound is
a) XY
b)
c)
d)

78) Which of the following fertilizers has the highest nitrogen percentage?
a) Ammonium sulphate
b) Calcium cyanamide
c) Urea
d) Ammonium nitrate

79) Simple distillation can be used to separate liquids which differ in their boiling points at least by
a)
b)
c)
d)

80) Lassaignes test for the detection of nitrogen fails in
a)
b)
c)
d)

81) An organic compound contains C = 40 %, O = 53.34 % and H = 6.60 %. The empirical formula of the compound is
a)
b)
c)
d)

82) The compound that does not give a blue colour in Lassaignes test is
a) Aniline
b) Glycine
c) Hydrazine
d) Urea

83) The Lassaignes extract is boiled with dil. before testing for halogens because
a)
b)
c)
d)

84) The following is the percentage composition of a compound: Na = 16.08 %, C = 4.19 %, O = 16.78 % and = 62.95 %. Its molecular formula is
a)
b)
c)
d)

85) Dumas method involves the determination of nitrogen content in the organic compound in the form of
a)
b)
c) NaCN
d)

86) Impure glycerine is purified by
a) Steam distillation
b) Simple distillation
c) Vacuum distillation
d) None of the above

87) Beilstein test is used for
a) N
b) Cl
c) Na
d)

88) On analysis, a saturated hydrocarbon is found to contain 83.70 % carbon and 16.30 % hydrogen. The empirical formula will be (At. wt. of C = 12; At. wt. of H = 1)
a)
b)
c)
d)

89) When pieces of human hair are heated strongly with soda lime, the smell of ammonia can be detected. Which of the following conclusions can be drawn from this observation?
a) Ammonia is present in the human hair, in the free state
b) Hair contains nitrogen heterocycles
c) Hair contains amino acids
d) None of the above

90) Absolute alcohol is prepared by
a) Fractional distillation
b)
c) Azeotropic distillation
d) Vacuum distillation

91) The percentage of sulphur in an organic compound, 0.32 g of which produces 0.233 g of [At. wt. Ba = 137, S = 32] is
a) 1.0
b) 10.0
c) 23.5
d) 32.1

92) A hydrocarbon has C = 85.72 % and the remaining is H. The hydrocarbon may be
a)
b)
c)
d)

93) For the separation of two immiscible liquids which method is used?
a) Chromatography
b) Fractionating column
c) Fractional distillation
d) Separating funnel

94) A mixture of benzene and chloroform is separated by
a) Sublimation
b) Separating funnel
c) Crystallization
d) Distillation

95) 0.24 g of a volatile liquid on vaporization gives 45 ml of vapour at NTP. What will be the vapour density of the substance?
a) 95.39
b) 39.95
c) 99.53
d) 59.93

96) Liebigs method is used for the estimation of
a) Nitrogen
b) Sulphur
c) Carbon and hydrogen
d) Halogens

97) Nitrogen in an organic compound can be estimated by
a)
b)
c) Both the above methods
d) None of these methods

98) In Lassaignes test for nitrogen, the blue colour is due to the formation of
a) Potassium fericyanide
b) Sodium cyanide
c) Sodium ferrocyanide
d) Ferric ferrocyanide

99) Aniline is usually purified by
a) Chromatographic technique
b) Steam distillation
c) By addition of oxalic acid
d) Fractional crystallization

100) In Kjeldahls method, the nitrogen present is estimated as
a)
b) NO
c)
d)


Answer :

Related Posts
Leave a reply
What is the capital of Egypt ?