Multiple Choice Questions (MCQs) on Organic
Chemistry from Textbook
1. The branch of chemistry which deals with the hydrocarbons and their derivatives is known as
(a) Organic chemistry
(b) Inorganic chemistry
(c) Physical chemistry
(d) Biochemistry
2. The general formula of alkanes is
(a) CnH2n
(b) CnH2n+1
(c) CnH2n+2
(d) CnH2n–2
3. Which of the following is an alcohol?
(a) CH3CHO
(b) CH3CH2OCH3
(c) CH3OH
(d) HCOOH
4. Which of the following is saturated hydrocarbon?
(a) CH3CH=CH2
(b) CH3CH2CH3
(c) CH3C≡CH
(d) CH2=CH–C≡CH
5. The prefix “hept” stands for the …………carbon atoms.
(a) 2
(b) 5
(c) 7
(d) 9
6. The functional group –COOH is used for
(a) Alkynes
(b) Carboxylic acids
(c) Phenols
(d) Alcohols
7. Polyethene is
(a) Oil
(b) paper
(c) plastic
(d) wood
8. Acetic acid is obtained from
(a) Banana
(b) Dates
(c) Garlic
(d) Vinegar
9. CH3–CH2– is ………… radical.
(a) Methyl
(b) Ethyl
(c) n-propyl
(d) iso-propyl
10. Alkenes
(a) show same general formula as alkynes
(b) have carbon-carbon triple bond
(c) have carbon-carbon double bond
(d) are saturated hydrocarbons
Answers of MCQs on Organic Chemistry from Text Book
1. D
2. A
3. B
4. A
5. A
6. D
7. B
8. B
9. A
10. B
MCQs on chapter # 4 ….. Organic Chemistry from
External Source
1. The branch of chemistry which deals with the compounds of carbon is called:
(a) Physical chemistry
(b) Inorganic chemistry
(c) Organic chemistry
(d) Biochemistry
2. The first synthetic organic compound is:
(a) Methane
(b) Acetic acid
(c) Urea
(d) Ethane
3. The alkanes are also called:
(a) Acetylenes
(b) Paraffins
(c) Alkynes
(d) Olefins
4. Which is the functional group of alcohols?
(a) >C=O
(b) –X
(c) –OH
(d) –COOH
5. Which of the following molecules is alkane?
(a) C5H12
(b) C5H8
(c) C5H14
(d) C5H10
6. Methane is also known as:
(a) Kerosene
(b) Oil gas
(c) Marsh gas
(d) Gasoline
7. A process that breaks large molecules into smaller one is called:
(a) Knocking
(b) Refining
(c) Reforming
(d) Cracking
8. A series of compounds in which each member differs from the preceding one by a constant ratio of >CH2 or methylene group is called:
(a) Isomerism
(b) Monologous series
(c) Homologous series
(d) None of these
9. General formula for alkane is:
(a) CnH2n-2
(b) CnH2n
(c) CnH2n
(d) CnH2n+2
10. The number of isomers in butane is:
(a) 4
(b) 3
(c) 2
(d) 5
11. An atom or group of atoms present in a molecule and is responsible for chemical behaviour is called:
(a) Functional group
(b) Alkyl group
(c) Aryl group
(d) Alkenyl group
12. Iso-butane possesses:
(a) Position isomerism
(b) Chain isomerism
(c) Functional isomerism
(d) Metamerism
13. Isomerism in which the compounds possess the same molecular formula but different arrangement of carbon atoms in the hydrocarbon chain is called:
(a) Chain isomerism
(b) Position Isomerism
(c) Functional Isomerism
(d) Metamerism
14. Which is pure carbon?
(a) Coke
(b) Coal tar
(c) Coal gas
(d) None of these
15. Residue left after fractional distillation of coal tar:
(a) Coke
(b) Pitch
(c) Coke
(d) None of these
16. Natural gas mainly consists of:
(a) Methane
(b) Propane
(c) Butane
(d) Ethane
17. The process in which the octane rating of gasoline can be increased is called:
(a) Reforming
(b) Cracking
(c) Isomerism
(d) Refining
18. Fraction of petroleum containing 10-13 carbons and its boiling range 150-230°C:
(a) Gasoline
(b) Natural gas
(c) Light oil
(d) Kerosene
19. The property of self-linkage among identical atoms to form long chain compounds is known as:
(a) Catenation
(b) Isomerisation
(c) Superposition
(d) Halogenation
20. Which of the following is the molecular formula of cyclobutane?
(a) C4H10
(b) C4H6
(c) C4H8
(d) C4H4
21. How many number of carbon atoms are joined in a spherical molecule of buckminsterfullerene?
(a) 30
(b) 60
(c) 90
(d) 120
22. Identify the most unsaturated compounds from the following.
(a) Propane
(b) Propene
(c) Propyne
(d) Chloropropane
23. Complete combustion of a hydrocarbon gives
(a) CO+H₂O
(b) CO₂+H₂O
(c) CO+H₂
(d) CO₂+H₂
24. Buckminsterfullerene is an example of………of carbon
(a) An isomer
(b) An isotope
(c) A functional group
(d) An allotrope
25. Butanone is a four-carbon compound with the functional group ______
(a) Carboxylic acid
(b) Aldehyde
(c) Ketone
(d) Alcohol
26. Fraction of petroleum containing C21-C40 and boiling range is above 400°C is:
(a) Paraffin wax
(b) Bitumen
(c) Light oil
(d) Heavy oil
27.The oils that have been carefully purified and decolourized act as mild laxative are:
(a) Light oil
(b) Gasoline
(c) Heavy oil
(d) Kerosene
28 The first member of alkene series is:
(a) Methane
(b) Ethyne
(c) Ethane
(d) Ethene
29. The hydrocarbons in which carbon atoms are arranged in rings are called:
(a) Aromatic
(b) Aliphatic
(c) Alicyclic
(d) None of these
30. The quality of petrol is measured by:
(a) Decane number
(b) Cracking
(c) Octane number
(d)Reforming
31. The first member of alkyne series is:
(a) Acetylene
(b) Methane
(c) Ethane
(d) Ethene
32. Preparation of ethene from ethyl alcohol is an example of:
(a) Dehalogenation
(b) Dehydration
(c) Halogenation
(d) Hydration
33. The hydrocarbons which possess double bond in their molecules are called:
(a) Alkenes
(b) Alkanes
(c) Paraffins
(d) Alkynes
34. The hydrocarbons which contain one or more double or triple bonds are called……. hydrocarbons:
(a) Unsaturated
(b) Paraffins
(c) Saturated hydrocarbons
(d) Arenes
35. Compounds which contain only carbon and hydrogen elements are called:
(a) Carbohydrates
(b) Substituted alkanes
(c) Hydrocarbons
(d) Halides
36. Soaps are formed by saponification of
(a) Carboxylic acids
(b) Glycosides
(c) Simple esters
(d) Alcohols
37. Which of the given is not an aliphatic hydrocarbon?
(a) Ethene
(b) Ethane
(c) Propyne
(d) Benzene
38. The isomeric pair is
(a) Ethane and propane
(b) Propane and butane
(c) Butane & 2-methylpropane
(d)Ethane & ethane
39. In
which of the given compounds -OH is the functional
group?
(a) Butanone
(b) Butanol
(c) Butanoic acid
(d)
Butanal
(a) Alcohol
(b) Phenol
(c) Alkene
(d) Alkyne
75. The general formula for amines is
(a) R-ch2
(b) R2ch
(c) R-nh2
(d) R-cooh
76. In which of the following groups, oxygen is attached on both sides with carbon atoms?
(a) ketone group
(b) ether group
(c) aldehyde group
(d) ester group
77. Vinegar is a solution of
(a) 50% – 60% acetic acid in alcohol
(b) 5% – 8% acetic acid in alcohol
(c) 5% – 8% acetic acid in water
(d) 50% – 60% acetic acid in water
78. Which is not correct for isomers of a compound?
(a) They differ in physical properties
(b) They differ in chemical properties
(c) They have same molecular formula
(d) They have same structural formula
79. The soap molecule has a …….…… and a ………..
(a) hydrophobic tail
(b) Hydrophobic head and a hydrophilic tail
(c) Hydrophobic head and a hydrophobic tail
(d) Hydrophilic head and a hydrophobic tail
(a) oh group to hydrocarbon chain
82. In naming alkane the stem or root chain tells about the
(a) number of hydrogen atoms
(d) number of bonds
85. Carbonization process is the conversion of
(a) coal into coal gas
(b) coal into wood
(c) wood into coal
(d) wood into coal tar
Explanation; (c)
The process of
conversion of wood into coal by biochemical process is known as Carbonization.
Carbonization is the term for the conversion of an organic substance into carbon or a carbon-containing residue through pyrolysis or destructive distillation. It is often used in organic chemistry with reference to the generation of coal gas and coal tar from raw coal.
86. The non-polar nature of hydrocarbons is due
(a) High electronegativity difference between C and H
(b) Low electronegativity difference between C & H
(c) Both a and b (d) None of them
Explanation; (b)
The hydrocarbons have only C and H atoms and there is very small electronegativity difference between them. That’s why they are non-polar in nature.
87. Condensed structural formula for n-butane is
(a)CH3−CH(CH3)2
(b) CH3−CH2−CH2−CH3
(c) CH3−CH2−CH2−CH2−CH3
(d) CH3−C(CH3)3
Explanation; (b)
n-butane is a straight chain 4 carbon alkanes whose Condensed structural formula is CH3−CH2−CH2−CH3.
88. Formic acid contains
(a) –OH
(b) –CO
(c) –COOH
(d) –CHO
Explanation; (c)
carboxylic acids are alkane derivatives obtained by replacing its one H atom by a carboxylic group (−COOH). Formic acid is the first member of the family of carboxylic acids containing −COOH carboxyl functional group.
89. Excessive burning of fossil fuels is a major cause of _______
(a) Air pollution
(b) Ozone thickening
(c) Noise pollution
(d) Water pollution
90. Which of the following is the functional group of organic acids?
(a) Ether group
(b) Aldehydic group
(c) Carboxylic group
(d) Ketone group
91. The number of covalent bonds in pentane (C5H12) is
(a) 18
(b) 17
(c) 16
(d) 15
92. To which homologous series C3H8 belongs?
(a) Alkanes
(b) Alkenes
(c) Cycloalkanes
(d) Alkynes
93.Which one of the following pair represents unsaturated hydrocarbons?
(a) C4H8 and C5H12
(b) C5H10 and C4H8
(c) C3H4 and C4H10
(d) None of them
94.Which one of the following pair
represents alkenes?
(a) C4H8 and C5H10
(b) C3H6 and C6H12
(c) C2H4 and C7H14
(d) All of them
95. Ethanol on complete oxidation gives:
(a) Ethanal and water
(b) CO2 and water
(c) CO and water
(d) C and water
96. Which of the following belongs to the homologous
series of alkynes?
(I) C2H2 (II) C3H6 (III) C4H6 (IV) C5H12
(a) I and II only
(b) I and III only
(c) II and IV only
(d) III and IV only
97. Which of the following members belong
to the same homologous series?
(a) C2H5OH and C3H7OH
(b) CH3OH and CH3Cl
(c) C2H4 and CH4
(d) HCHO & HCOOH
98. The difference in the molecular
formula and molecular mass of CH4 and C2H6 is
(a) CH3 and 14 amu
(b) CH3 and 12 amu
(c) CH2 and 12 amu
(d) CH2 & 14 amu
99. Which among the following contains
triple bond?
(a) C2H4
(b) C2H6
(c) C3H8
(d) C7H12
100. Propane and butane as liquid are used in
(a) LSG
(b) ECG
(c) LPG
(d) LNG
SOLUTION
LPG is
primarily composed of propane, butane, isobutane and mixtures of these gases. LPG
exists as liquid or gas (vapour), depending on pressure and temperature.