ORG CHEM Flashcards
1
Q
Which among the following chemical bond were
described by Kossel and Lewis?
a) Metallic bond
b) Polar covalent bond
c) Coordinate bond
d) Ionic and Covalent bond
A
d) Ionic and Covalent bond
2
Q
State whether the given statement is true or false “Ionic bonds are non-directional”
a) True
b) False
A
a) True
3
Q
If a bond is made up of a large number of organic
compound, then the bond is termed as?
a) Ionic bond
b) Metallic bond
c) Covalent bond
d) Dipolar bond
A
c) Covalent bond
4
Q
Which among the following is not an example of
hydrogen bond?
a) H20
b) Liquid HCl
c) NH3
d) CHCl3
A
b) Liquid HCl
5
Q
Atoms undergo bonding in order to ?
a) Attain stability
b) Lose stability
c) Move freely
d) increase energy
A
a) Attain stability
6
Q
An atom differs from its ion in which among the
following ?
a) Mass number
b) Atomic number
c) Neutrons
d) Number of protons
A
d) Number of protons
7
Q
Which among the following is both a molecule and a
compound?
a) C6 H12 O6
b) H2O
c) CO2
d) NaCl
A
b) H2O
8
Q
Bond energy and the corresponding bond length vary
directly with each other. comment whether the statement
is true or false.
a) True
b) False
A
b) False
9
Q
The energy which must be transferred to any atom to
dislodge an electron is called?
a) Free energy
b) Ionization Energy
c) Quantum mechanical energy
d) Dissociation Energy
A
b) Ionization Energy
10
Q
Potassium Ion K+ has the same electronic configuration
as that of which noble gases mentioned below ?
a) Krypton
b) Xenon
c) Argon
d) Radon
A
c) Argon
11
Q
Ten covalent bonds in the Lewis structure of Propane
will account for how many valence electrons?
a) 10
b) 20
c) 14
d) 12
A
b) 20
12
Q
What is the hybridization of oxygen in water?
a) sp
b) sp2
c) sp3
d) sp3d
A
c) sp3
13
Q
The electronegativity difference between the covalently
bonded atoms is
a) Less than 0
b) 0-0.3
c) 0.3-1.7
d) Over 1.7
A
b) 0-0.3
14
Q
What is the hybridization of Carbon atom in CF4?
a) sp2
b) sp
c) sp3d
d) sp3
A
d) sp3
15
Q
Which one has zero dipole moment?
a) C6H6
b) NH3
c) H2S
d) NO
A
Answer: a
Explanation: The ring of benzene is completely closed and
is of perfect stability and hence it has zero dipole moment.
16
Q
Which one have both sigma and pi bonds?
a) H2S
b) NO2
c) HClO
d) NaCN
A
Answer: d
Explanation: In NaCN both double bond and triple bond is
present and hence it has both sigma
and pi bonds.
17
Q
PH3, So3, and HF are examples of polar molecules. State
true or false
a) True
b) False
A
Answer: b
Explanation: SO3 is not an example of polar molecule as it
does not contain a hydrogen bond.
18
Q
What is the hybridization of sulphur in H2S?
a) sp
b) sp2
c) sp3
d) sp3d
A
Answer: c
Explanation: S has two pairs of electrons and two atoms
bonded to H with a total of 4 electrons and hence it has a
hybridization of sp3.
19
Q
Name the geometry of the central oxygen atom in the
ozone molecule (o3)
a) Trigonal planar
b) Linear
c) Tetrahedral
d) Pyramidal
View Answer
A
Answer: a
Explanation: It forms a single bond with one oxygen atom,
double bond with another oxygen atom and there exists
one more non-bonded atom. Thus, it forms a trigonal
planar structure.
20
Q
In which molecule there is a complete linear
arrangement of all atoms?
a) BF3
b) NH3
c) CO2
d) CH4
A
Answer: c
Explanation: BF3 has trigonal planar structure,NH3 has a
trigonal bipyramidal structure, CH4 has tetragonal
structure and hence CO2 is the one with linear structure.
21
Q
Choose the one which is incorrect
a) BrO4 – tetrahedral
b) PF3 – pyramidal
c) ClO4 – tetrahedral
d) BeBr2 – linear
A
Answer: b
Explanation: PF3 has a trigonal pyramidal structure as it
has three bonding pairs and one non-bonding pair
22
Q
A crystalline solid possess which one of the following
property?
a) Irregularity
b) Non- symmetric
c) Perfect geometric pattern
d) non- stability
A
Answer: c
Explanation: A crystalline solid is one which possesses
perfect geometry, high stability, symmetric and regularly
arranged.
23
Q
Melting is process which can be stated by the below
statements except,
a) Change from a highly disordered stated to an ordered
state
b) Change from particles in crystal lattice to liquid state
c) Thermal energy of particles overcome the
intercrystalline forces that hold them
d) Change from low temperature to high temperature
A
Answer: a
Explanation: Melting is a process which proceeds by
changing from a highly ordered state to a disordered state.
24
Q
Which among the following statement is not true?
a) In liquid, particles are less regularly arranged and are
free to move
b) Boiling involves breaking up of group of molecules in
liquid
c) Boiling involves clubbing of oppositely charged ions
d) Thermal energy of particles overcome cohesive forces
that hold them
A
Answer: c
Explanation: Boiling involves separation of oppositely
charged ions and makes them as individual ions
25
Which among the following is not associated with
intermolecular forces?
a) They hold neutral molecules
b) Non- electrostatic in nature
c) attraction of oppositely charged particles
d) dipole-dipole interaction and van der Waals forces
Answer: b
Explanation: Intermolecular forces are electrostatic in
nature.
26
When one of the Hydrogen in Methane( CH4) is
replaced by a hydroxyl group, then structurally methane
resembles?
a) Methanol
b) Ethanol
c) Water
d) Both methanol and water
Answer: d
Explanation: Like water, it is a liquid with boiling point
which is abnormally high for a compound of its size and
polarity.
27
Which among the following does not match with the
term solubility?
a) The structural units get separated from each other
b) The ion-dipole bond is very strong
c) The spaces in between the structures are occupied by
solvent molecules
d) The electrostatic attraction between the oppositely
charged ions and their corresponding ends are called iondipole bond
Answer: b
Explanation: The bond is weak but in the aggregate they
supply enough energy to overcome the interionic forces.
28
A Strong acid is same as concentrated acid. State true or
false
a) False
b) True
Answer: a
Explanation: Concentration of an acid depends upon the
water content whereas the strength of an acid depends on
dissociation power.
29
When an acid reacts with a metal, which one of the
following gas is usually liberated?
a) ammonia gas
b) chlorine
c) oxygen
d) Hydrogen gas
Answer: d
Explanation: When metal reacts with acid, a soap bubble is
formed and the bubble contains Hydrogen gas (example:
HCl, H2SO4)
30
Select the one which is wrongly mapped
a) Sodium carbonate – Washing soda
b) Sodium chloride – common salt
c) Calcium carbonate – slaked lime
d) Sodium hydroxide – caustic soda
Answer: c
Explanation: calcium hydroxide is commonly referred as
slaked lime.
31
What is the pH of 0.0001 molar HCl solution?
a) 1
b) 2
c) 3
d) 4
Answer: d
Explanation: It has a H+ concentration of 10-4
. The value of
negative exponent(^-4) gives pH value to be 4.
32
Choose the incorrect option regarding Isomerism:
a) They differ in both physical and chemical properties
b) They have the different molecular formula
c) There are two types of Isomerism : Structural and Stereo
Isomerism
d) Geometric and optical isomerism are two types of
Stereo Isomerism
Answer: b
Explanation: Isomers are compounds that have same
molecular formula.
33
What will be the product when HNO3 reacts with
NH4OH ?
a) NH4 NO3
b) 2NH4 NO3
c) NH4 (NO3)
Answer: a
Explanation: the reaction takes place as follows:
HNO3 + NH4OH —-> NH4NO3 + H2O.
34
Find the odd one out:
a) Neutral salt : NaCl
b) Acid salt : CuSO4.5H2O
c) Basic salt: CuCO3.Cu(OH)2
d) Nonhydrated salt: KNO3
Answer: b
Explanation: CuSO4.5H20 is a hydrated salt. An example of
acid salt is NaHCO3.
35
Isomerism that arises out of the difference in spatial
arrangement of atoms or groups about the doubly bonded
carbon atoms are called? (In specific)
a) Structural Isomerism
b) Stereo Isomerism
c) Geometrical Isomerism
d) Optical Isomerism
Answer: c
Explanation: These geometrical isomers are not mirror
images of each other and they differ in spatial
arrangement from one another.
36
Isomers with similar groups on the same side are called
as ” trans” isomers. State true or false
a) True
b) False
Answer: b
Explanation: “Trans” isomers are those with similar groups
arranged in opposite direction. The Isomers with similar
groups on the same side are called as “cis” isomers.
37
Which among the following defines Meso forms of
isomers
a) Meso form is optically inactive due to external
compensation
b) The molecules of the meso isomers are chiral
c) It can be separated into optically active enantiometric
pairs
d) It is a single compound
Answer: d
Explanation: Meso forms of isomers are single compound
and their molecules are achiral
and hence they cannot be separated into pairs.
38
Which among the following does not exhibit geometric
isomerism
a) 1-hexene
b) 2-hexene
c) 3-hexene
d) 4-hexene
Answer: a
Explanation: Alkenes like 1-hexene when flipped from top
to bottom they have identical structures and also they
have C=CH2 unit which does not exist as cis- trans isomers.
39
Which among the following is formed when an alcohol is
dehydrated?
a) alkane
b) alkyne
c) alkene
d) aldehyde
Answer: c
Explanation: In elimination reaction, when protic acids
react with alcohol, they lose water molecule to form
alkenes.
40
A fat on hydrolysis would yield?
a) Glycerol and soap
b) Ethanol and soap
c) Ethanol and glycerol
d) Only soap
Answer: a
Explanation: During saponification process, fat on
hydrolysis will yield glycerol and soap
41
Which among the following correctly defines
Diastereomer?
a) These have same magnitude but different signs of
optical rotation
b) Nonsuperimposable object mirror relationship
c) These differ in all physical properties
d) Separation is very difficult
Answer: c
Explanation: Diastereomers differ in all physical properties.
The rest of the points are related to Enantiomers.
42
Ethane is obtained by electrolyzing
a) Potassium formate
b) Potassium succinate
c) Potassium acetate
d) Potassium fumarate
Answer: b
Explanation: By electrolyzing potassium succinate (the
process is generally called Kolbe’s electrolysis), ethane is
obtained.
43
“Methane is a product of aerobic respiration”. State
true or false
a) False
b) True
Answer: a
Explanation: Methane is the end product of anaerobic
decay of plants due to the breakdown of very complicated
molecules.
44
Calcium carbide on reaction with water gives?
a) Methane
b) Ethane
c) propane
d) Acetylene
Answer: d
Explanation: CaC2 + H20—-> C2H2 + Ca(OH)2.
45
The hydrocarbon in which all the 4 valencies of carbon
are fully occupied is called as
a) Alkene
b) Alkyne
c) Alkane
d) Cycloalkane
Answer: c
Explanation: Alkanes , the saturated hydrocarbons are
those in which the carbon atoms are bonded covalently to
each other (fully occupied). Each carbon atom is
tetrahedrally surrounded by H-atoms
46
Name the process associated with acylation of benzene
a) Friedel craft reaction
b) Wurtz reaction
c) Wurtz fitting reaction
d) Debey Huckel reaction
Answer: a
Explanation: The electrophilic substitution reaction that
takes place between ethanoyl chloride and benzene is
called as Friedel craft reaction
47
Liquid hydrocarbon is converted into gaseous
hydrocarbon by:
a) Oxidation
b) Hydrolysis
c) Cracking
d) Distillation
Answer: c
Explanation: Under cracking with high temperature, the
liquid form of hydrocarbon is converted into gaseous form
48
Chlorination of alkanes is an example of
a) Radical
b) Elimination
c) Free radical
d) Addition
Answer: c
Explanation: Free radical chlorination is a reaction that
substitutes a chlorine for a hydrogen on an alkane
49
When chlorine gas reacts with methane, the product
formed is
a) CHCl
b) CH2Cl
c) CH3Cl
d) CH4Cl
Answer: c
Explanation: Under the influence of UV light or with a temperature of 250-400(degree) chlorine and methane
react vigorously to give hydrogen chloride and
chloromethane (CH3Cl).
50
Methane reacts more readily with chlorine than with
Fluorine. State true or false
a) True
b) False
Answer: b
Explanation: Methane reacts with chlorine but not as
vigorously as with fluorine. The reactivity order is as
follows: F2 > Cl2 > Br2 >I2.
51
The methyl chloride undergoes substitution to form
a) CHCl
b) CH2Cl
c) CHCl2
d) CH2Cl2
Answer: d
Explanation: Chloromethane undergoes further
substitution to form hydrogen chloride and
dichloromethane (CH2Cl2).
52
Identify the one which is not a type of chlorination
a) Free radical chlorination
b) Electrophobic chlorination
c) Ketone chlorination
d) Chlorine addition reaction
Answer: b
Explanation: Electrophobic is not a kind of halogenation. It
is electrophilic chlorination, in which aromatic
substitutions takes place.
53
Which among the following on chlorination undergoes
substitution at the alkyl group
a) Ethers
b) Hydroxyl groups
c) Carbonyl compounds
d) Carboxylic acids
Answer: a
Explanation: In the absence of sunlight, the alpha
hydrogen of ethers undergoes substitution when treated
with chlorine.
54
In the presence of red phosphorous, chlorine converts
the fatty acids having alpha hydrogen atoms into
a) Halo acids
b) Alpha-halo acids
c) Alpha,alpha-dihalo acids
d) Trihalo acids
Answer: b
Explanation: The propionic acid, in the presence of Cl2/P
gets converted into alpha chloro propionic acid due to the
action of the halogen chlorine.
55
Chlorine in the presence of which among the following
generates positively charged species?
a) Ferric chloride
b) Anhydrous ferric chloride
c) Ferrous chloride
d) Anhydrous ferrous chloride
Answer: b
Explanation: Ferric chloride is a lewis acid catalyst and in
the presence of chlorine, it converts nitrobenzene into 3-
chloro nitro benzene.
56
p-nitrotoluene on reaction with chlorine forms
hydrogen chloride and
a) p-Nitrobenzyl chloride
b) o-Nitrobenzyl chloride
c) m-Nitrobenzyl chloride
d) Nitrobenzyl chloride
Answer: a
Explanation: p-Nitrotoluene reacts with chlorine in the
presence of CCl4 at 80 (degree) C to form p-nitrobenzyl
chloride under the conditions of photochemical initiation.
57
Chlorination of cyclobutane gives which among the
following in addition to hydrogen chloride
a) Cyclobutyl chloride
b) Cyclobutyl chlorite
c) 1-chlorobutene
d) 1,1-chlorobutene
Answer: b
Explanation: All the hydrogens of cyclobutane are
equivalent and substitution of any gives the same product
as that of others.
58
The step in which Cl-Cl bond homolysis occurs is called:
a) Initiation step
b) Propagation step
c) Intermediate step
d) Termination step
Answer: a
Explanation: Each Cl atom in the initiation step has several
valence electrons and is very reactive and hence it
abstracts a hydrogen atom from methane and homolysis
occurs
59
The rate of the reaction is equal to the product of three
factors listed below except
a) Collision frequency
b) Energy factor
c) Orientation factor
d) pH factor
Answer: d
Explanation: The reaction rate is given by the product of
collision frequency (deals with concentration, pressure,
and arrangement), energy factor ( deals with distribution
of kinetic energy), and orientation factor (probability
factor).
60
Temperature and pressure are the only factors which
affect the reaction rate. state true or false
a) True
b) False
Answer: b
Explanation: The rate of reaction is affected by three
factors temperature, pressure, and concentration. All the
three varies directly with the rate of the reaction.
61
The frequency of molecular collision increases if
a) The concentration of product increases
b) The concentration of product decreases
c) The concentration of reactant increases
d) The concentration of reactant decreases
Answer: c
Explanation: The frequency of molecular collision increases
varies directly with the concentration of the reactant
62
Identify the true statement regarding catalyst
a) Always decreases the rate of the reaction
b) Always increases the activation energy of the reaction
c) Actually participates in the reaction
d) Changes the equilibrium concentration of the product
Answer: c
Explanation: A catalyst is a substance which when added,
only alters the reaction rate temporarily and does not
have a permanent effect on them
63
Which among the following catalyst increases the rate
of the reaction
a) Calcium carbonate
b) Calcium chloride
c) Calcium hydroxide
d) Calcium sulphate
Answer: a
Explanation: Calcium carbonate has large surface area and
hence it increases the reaction rate.
64
Which is not a type of catalyst:
a) Positive catalyst
b) Negative catalyst
c) Autocatalyst
d) homogeneous catalysis
Answer: d
Explanation: Homogeneous catalysis is a phenomenon in
which the catalyst takes part in the reaction and it is not a
type of catalyst.
65
Identify the correct alkane name for the molecular
formula C30H62
a) Propdecane
b) Eicosane
c) Triacontane
d) Dodecane
Answer: c
Explanation: Triacontane is the alkane with the molecular
formula C30H62 as alkanes have the general formula
CnH2n+2.
66
Identify the smallest alkane which can form a ring
structure (cycloalkane)
a) Cyclomethane
b) Methane
c) Cyclopropane
d) Propane
Answer: c
Explanation: Cyclopropane is the only smallest alkane that
can form a successful ring structure with C-C bond on
removal of a hydrogen atom.
67
In which among the following alkane, a carbon atom is
displaced so as to form a compactly structure with the
resemblance of a butterfly wing
a) Cyclopropane
b) Cyclobutane
c) Cyclopentane
d) Cyclohexane
Answer: b
Explanation: If one of the carbon atoms of cyclobutane is
not displaced, then the C-C bond would be exactly at right
angles to each other and they do not form a cyclic
structure.
67
Dienes are the name given to compounds with
a) Exactly a double bond
b) Exactly a triple bond
c) Exactly two double bond
d) more than two double bond
Answer: c
Explanation: Alkenes are the name given to compound
with one double bond and dienes are the one given to
compounds with two double bond.
68
The first step in IUPAC nomenclature is to identify the
total number of carbon atoms present in the compound.
State true or false
a) True
b) False
Answer: b
Explanation: The first step is to find the number of carbon
atoms present only in the main/ longest chain of the
compound.
69
The substituent in the chain is named by replacing the
“ane” in the alkanes by
a) ene
b) ic
c) one
d) yl
Answer: d
Explanation: ene, ic and one are used for representing
alkenes, carboxylic acids, and ketones respectively, hence
yl is the term which is to be substituted in place on ane in
the alkanes.
70
The C=C bond in the chain of the compound considered
is shown by
a) Specifying the number of carbon atoms associated with
the bond
b) Specifying the number of carbon atoms at beginning of
the C=C bond
c) Specifying the number of carbon atoms at end of the
C=C bond
d) Specifying the number of carbon atoms in the entire
chain
Answer: b
Explanation: According to the rules of IUPAC, The C=C
bond in the chain of the compound considered is shown
by specifying the number of carbon atoms at beginning of
the C=C bond.
71
Triple bond with two carbon atoms on either side is
called
a) Methnyl group
b) Ethynyl group
c) Propionyl group
d) Propargyl group
Answer: b
Explanation: Triple bond with two atoms on either side are
called as ethynyl group and those with one carbon on one
side and two carbon on another side are called as
propargyl group
71
The substituent groups that are commonly associated
with benzene ring are
a) Phenyl and benzyl
b) Propyl and phenyl
c) Methyl and benzyl
d) Butyl and phenyl
Answer: a
Explanation: Phenyl and benzyl are commonly associated
with benzene ring due to their closely associated structure
with difference in hydrogen atom
72
Organic compounds are broadly classified as
a) Open chain compounds and acyclic compounds
b) Open chain compounds and linear chain compounds
c) Cyclic compounds and alicyclic compounds
d) alicyclic compounds and acyclic compounds
Answer: d
Explanation: Organic compounds are broadly classified
into open chain and closed chain compounds
73
Aliphatic compound is the other name for
a) Acyclic compounds
b) Alicyclic compounds
c) Ring compounds
d) Closed chain compounds
Answer: a
Explanation: open chain compounds or acyclic compounds
are otherwise called as aliphatic compounds.
74
Which among the following is not an example of Acyclic
compound
a) Acetaldehyde
b) Ethane
c) Cyclopropane
d) Isobutane
Answer: c
Explanation: Cyclopropane is a ring (cyclic) compound and
hence it does not come with the examples of open chain
compounds.
75
Which among the following is not an example of alicyclic
compound
a) Cyclohexane
b) Cyclohexene
c) Tetrahydrofuran
d) Acetic acid
Answer: d
Explanation: Acetic acid is a linear chain compound
(acyclic) and hence it is not an example of ring compound
(alicyclic).
76
Which among the following is not an aromatic
compound(in specific)
a) Naphthalene
b) Aniline
c) Pyridine
d) Tropolone
Answer: c
Explanation: Pyridine is heterocyclic aromatic compound.
Whereas naphthalene and aniline are benzenoid aromatic
compounds and tropolone is a non-benzenoid aromatic
compound.
77
Find the odd one among the following:
a) Alicyclic compounds
b) Heterogeneous compounds
c) Branched chain compounds
d) Aromatic compounds
Answer: c
Explanation: Branched chain compound is a classification
of open-chain compounds. Whereas, alicyclic, aromatic
and heterogeneous compounds are sub-classifications of
cyclic compounds.
78
Identify the odd one among the following
a) Indene
b) Anthracene
c) o,m,p-xylene
d) Azulene
Answer: d
Explanation: Azulene is a non- benzenoid compound.
Whereas, Indene, anthracene, and o,m,p-Xylene are
examples of benzenoid aromatic compounds.
79
Organic compounds can be classified even based upon
the function groups. Identify the one which is not a
functional group
a) Isocyanide
b) Isocyano
c) Carboxyl
d) Carbonyl
Answer: a
Explanation: Isocyanide is a compound and it is not a
functional group.
80
Which among the following is not a class of organic
compound
a) Carbonyl compound
b) Nitro compound
c) Amides
d) Electro compounds
Answer: d
Explanation: Classes of organic compounds are those
which involves organic compounds such as carbon,
hydrogen and oxygen. Hence, electro compounds is not a
class of organic compounds.
80
Which among these is not associated with aliphatic
compounds
a) They contain (4n+2)pi electrons
b) Contain straight chain compounds
c) Contain branched chain compounds
d) Has appropriate number of H-atoms and functional groups
Answer: a
Explanation: The aromatic compounds (4n+2)pi electrons,
which comes under the classification of cyclic compounds
and hence they are not associated with aliphatic
compounds.
81
Resonance forms are in equilibrium with each other.
State true or false
a) True
b) False
Answer: b
Explanation: Resonance forms are hybrid in nature and
hence it is not correct to say that they are in equilibrium
with each other.
82
Identify the false statement regarding resonance
a) As the number of charges increases, the resonance
forms gets more significant
b) Zero charge of resonance is the most significant one
c) Atoms with full octet resonance form are more stable
when compared with the one with unfilled octet
d) Resonance is unstable in case of unfilled octet of
nitrogen atom
Answer: a
Explanation: Greater the number of charges, less stable
and less significant gets the resonance form.
83
Identify the correct sequence according to
electronegativity
a) F> NH2> CH3>OH`
b) NH2`> F`>CH3`> OH`
c) NH2`>OH`> CH3`>F`
d) F`> OH`>NH2`>CH3`
Answer: d
Explanation: In the sequence ” F`> OH`> NH2`> CH3`”, F’ is
the most stable one and CH3′ is the least stable one, as the
stability of the anions increases on moving towards the
right of the periodic table
84
Identify the correct sequence with respect to Inductive
effects
a) CF3`> CH2F`> CHF2`> CF3`
b) CF3`> CHF2`> CH2F`> CH3`
c) CH3`> CH2F`> CHF2`> CF3`
d) CH3`> CHF2`> CH2F`v CF3`
Answer: b
Explanation: As electron withdrawing substituent is
greater in CF3, it is more stable and CH3 is the least stable
one and hence the sequence
85
Stability sequence: primary carbocation> secondary
carbocation > tertiary carbocation.
Is this sequence correct?
a) Yes
b) No
Answer: b
Explanation: The tertiary carbocation has the highest
stability and the primary carbocation has the least
stability, as it lies close to electron withdrawing group and
hence the sequence is not correct.
86
Identify the incorrect statement regarding aromaticity
a) It is the extra stability possessed by a molecule
b) p-orbitals must be planar and overlap
c) Cyclic delocalization takes place
d) It does not follow Huckel’s rule
Answer: d
Explanation: It follows Huckel’s rule, according to which a
molecule must possess specific number of pi electrons
within a closed ring of p-orbitals.
87
Aromatic rings do not have resonance structures. State
true or false
a) False
b) True
Answer: a
Explanation: Aromatic rings have resonance structure due
to cycling double bonds and all aromatic rings must have
resonance but the converse need not be satisfied.
88
Select the correct statement regarding the aromatic
nitrogen molecule
a) It is not hybridized
b) It is sp hybridized
c) It is sp2 hybridized
d) It is sp3 hybridized
Answer: c
Explanation: As a result of its overall structure and
electron delocalization, it becomes a sp2 hybridized,
aromatic molecule
89
Can a linear molecule have aromaticity?
a) Yes
b) No
Answer: b
Explanation: A molecule can have aromaticity if it is closed
loop or ring-shaped or has p-orbitals and hence linear
molecule cannot have aromaticity.
90
Select the incorrect statement:
a) A resonance may sometimes cause sp3 atoms to
become sp2 hybridized
b) Delocalizing one lone pair causes aromaticity
c) One lone pair will be counted as two pi electrons
according to Huckel’s equation
d) Two sigma bonds make up a double bond
Answer: d
Explanation: A double bond is one which has a sigma bond
and a pi bond. Each pi bond has two pi electrons
91
Identify the one which does not come under the organic
addition reaction
a) Hydration
b) Dehydration
c) Halogenation
d) Hydrohalogenation
Answer: b
Explanation: Dehydration comes under elimination
reaction and hence it does not come under addition
reaction.
92
Choose the correct one which will react faster in the
SN2 nucleophilic substitution reaction
a) CH2-CH=CH2=Br
b) CH2 = CH- CH2 – Br
c) CH2 = CH- CH2 = Br
d) CH= CH2 – CH2 – Br
Answer: b
Explanation: The carbocation character in the transition
state causes stabilization of the resonance and hence CH2
= CH- CH2 – Br (2- bromobutane) is the one which will
react faster compared to the others.
93
What will be the reactivity of chlorobenzene in an
electrophilic substitution reaction with benzene?
a) Reacts very slowly than benzene
b) Reacts in the same way as benzene
c) Reacts faster than benzene
d) Does not react with benzene
Answer: a
Explanation: The rate of the reaction depends on the
electron density in the ring and here in this case resonance
is not favorable and the electronegativity dipole
dominates. This slows down the reactivity of
chlorobenzene
94
Alcohol on refluxing with Cr2O7 gives:
a) Ester
b) Aldehyde
c) Sugar
d) Carboxylic acid
Answer: d
Explanation: Alcohol (R-OH), when it is refluxed with
Cr2O7, it forms carboxylic acid (R-COOH).
95
Alkene under high temperature and high-pressure forms
a) Alcohol
b) Polyalkyne
c) Polyalkane
d) Polyalkene
Answer:c
Explanation: Alkenes undergoes polymerization reaction
under high temperature and pressure to form poly alkanes
-(C-C)-n.
96
Select the incorrect statement regarding carboxylic acids
a) They form acyl chlorides on reaction with PCl5
b) Aldehydes in the presence of H+/ Cr2O7 forms
carboxylic acids
c) They combine with alcohols to form esters
d) Upon polymerization, they form polymers
Answer: d
Explanation: Carboxylic acids do not undergo
polymerization reaction.
96
Identify the one which on reaction with carboxylic acid
at high temperature gives Ester
a) Ketone
b) Alcohol
c) Aldehyde
d) Sugars
Answer: b
Explanation: Alcohols on reaction with carboxylic acid at
high temperature, in the presence of sulphuric acid gives
Ester.
97
Primary alcohols undergo what reaction to form
alkenes?
a) Elimination
b) Oxidation
c) Reduction
d) Hydrolysis
Answer: a
Explanation: Upon elimination or dehydration, the primary
alcohols form alkenes.
98
Answer: a
Explanation: Upon elimination or dehydration, the primary
alcohols form alkenes.
Answer: b
Explanation: Ketones in the presence of NaBH4 undergoes
reduction to form secondary alcohols.
99
Primary amides get converted into primary amines by:
a) Addition
b) Oxidation
c) Reduction
d) Acylation
Answer: b
Explanation: Primary amides upon heating in the presence
of hydrogen and nickel catalyst, gets reduced to form
primary amines.
100
Identify the one which does not come under the
chemical methods of quantitative analysis
a) Gravimetric
b) Titrimetric
c) Volumetric
d) Magnetic suceptibility
Answer: d
Explanation: Magnetic suceptibility comes under physical
methods of qunatitative analysis and hence the answer.
101
Quantitative analysis is one which is used for separating
out the specific constituents from a mixture. This
statement is:
a) True
b) False
Answer: b
Explanation: Quantitative analysis is used to measure the
quantity, (i.e the amount) present and the above
mentioned statement defines qualitative analysis.
102
Select the incorrect statement regarding analytical
balance
a) It is the fundamental kit in quantitative analysis
b) It measures samples very accurately
c) It could measure the difference in mass upto 0.1 mg
d) It is not a sensitive instrument
Answer: d
Explanation: It is a very sensitive instrument as it could
accurately measure the weight of a particular compound
of upto 0.1 mg
103
Which among the following is not a physical method:
a) X-ray fluorescence spectroscopy
b) Atomic emission spectroscopy
c) Inert gas fusion
d) Trace element analysis
Answer: c
Explanation: Inert gas fusion is an example of chemical
methods of quantitative analysis, as it involves chemical
reaction such as oxidation.
104
Select the inappropriate statement regarding
quantitative analysis
a) It helps in determining the outcome of the product
b) It helps in determining the impurities in the sample
c) It fails to indicate the presence of lead in some
compound
d) It could identify the amounts of dosage present in the
drug
Answer: c
Explanation: It can identify the presence of lead and could
also account for its concentration in case of paints and
toys.
105
. Identify the test which is not a part of qualitative
analysis:
a) Litmus test
b) Kastle-Meyer test
c) Iodine test
d) Flame test
Answer: a
Explanation: Kastle-meyer test is done for identification of
blood, Iodine test is done for identification of starch and
Flame test is done to identify Barium.
106
Covalent molecules can be identified using quantitative
methods. State true or false
a) False
b) True
Answer: a
Explanation: The qualitative analysis is used to identify
covalent molecules by distinguishing them using physical
properties such as melting point, etc.
107
Identify the reagent which is not commonly used in
qualitative analysis
a) 6M NaOH
b) 6M HCl
c) 6M HNO3
d) 6M NH4
Answer: d
Explanation: 6M NH3 (not NH4) is the reagent commonly used in
qualitative analysis because it is used in almost every
group procedures.
108
Select the correct statement about the reagent 6M
HNO3
a) It forms hydroxo complexes
b) It destroys hydroxo and ammonia complexes
c) It forms NH3 complexes
d) It decreases the H+ ion concentration
Answer: b
Explanation: It is a good oxidizing agent, dissolves in
insoluble hydroxides and it destroys hydroxo and ammonia
complexes
109
Identify the incorrect statement regarding the reagent
6M NH3
a) It increases hydroxide and NH3 concentration
b) It decreases H+ concentration
c) It is capable of precipitating insoluble hydroxides
d) It is capable of forming hydro complexes
Answer: d
Explanation: It forms only NH3 complexes and does not
form hydro complexes.
110
Select the minimum number of carbon atoms, a
molecule must possess so as to be regarded as a higher
alkane
a) 15
b) 16
c) 17
d) 18
Answer: c
Explanation: A molecule with more than 17 carbon atoms
are regarded as higher alkanes such as waxes and solids.
111
Which among the following is not an alkane isomer with
6 carbon atoms
a) Hexane
b) 2,3-dimethylbutane
c) 2,2-dimethylbutane
d) Neopentane
Answer: d
Explanation: Neopentane is an isomer with 5 carbon atoms
and hence it is not an isomer with 6 carbon atoms.
112
The other name for branched chain alkanes is
a) Paraffins
b) Isoparaffins
c) Neoparaffins
d) Naphthenes
Answer: b
Explanation: Linear and branched chain alkanes have
difference in their physical properties and hence they are
given different prefix like n- and iso- respectively.
113
Select the incorrect statement regarding the boiling
points of alkanes
a) Boiling point increases with stronger Vander Waal’s
forces
b) Surface area is the only factor which determines the
boiling point of alkane
c) Boiling point of straight chain alkanes is greater than
that of branched chain alkanes
d) The boiling point of cycloalkanes is always higher than
that of linear alkanes
Answer: b
Explanation: Number of electrons and surface area are the
two factors which determine the boiling point.
114
Choose the correct statement :
a) Alkanes have poor conductivity
b) They form hydrogen bonds
c) They have good solubility in non polar solvents than
polar solvents
d) Alkanes have less density than that of water
Answer: b
Explanation: They undergo polarization and hence they do
not form hydrogen bonds.
115
Liquified petroleum gas is mainly composed of :
a) Methane and ethane
b) Ethane and propane
c) Propane and butane
d) Butane and hexane
Answer: c
Explanation: At low pressure both propane and butane
gets liquefied, hence they form the main components of
LPG
116
An alkane with 6 carbon atoms will have how many
hydrogen atoms?
a) 11
b) 12
c) 13
d) 14
Answer: d
Explanation: From the formula CnH2n+2, if n=6 then
(2*6)+2=14.
117
Which among these is not a structural isomer of the
compound C4H8
a) But-1-ene
b) But-2-ene
c) But-3-ene
d) 2-methylpropene
Answer: c
Explanation: The compound but-3-ene have a structural
formula different from the above three and hence it is not
a structural isomer of C4H8.
118
Select the incorrect statement regarding alkenes
a) In alkenes, the carbons are connected by pi bonds
b) Alkenes have almost same physical properties as that of
the alkanes
c) Alkenes are less reactive than alkanes
d) Alkenes undergo polymerization reaction
Answer: c
Explanation: Alkenes are not less reactive than alkanes,
indeed they are very reactive compared with them due to
the presence of C=C.
119
Identify the addition reaction which is not undergone by
the alkenes
a) Mercuration
b) Oxymercuration
c) Hydroboration
d) Halogenation
Answer: a
Explanation: Alkenes do not undergo mercuration, indeed
they undergo oxymercuration , a process in which an
alkene is converted into an alcohol.
120
Identify the incorrect statement regarding the synthesis
of alkenes
a) Cracking of a hydrocarbon yields alkenes
b) The reactions are exothermic
c) Zeolite catalyst helps in the synthesis of alkenes
d) The synthesis of alkenes is otherwise known as
reforming
Answer: b
Explanation: The reactions takes place at high
temperatures and hence they are endothermic
121
The major alkyne, acetylene compound is produced by
which among the following application on natural gas
a) Hydrogenation
b) Partial oxidation
c) Cracking
d) Hydrohalogenation
Answer: b
Explanation: A huge quantity of acetylene is produced by
partial oxidation of the natural gas.
122
Which among the following alkynes is used as a rocket
fuel?
a) Ethyne
b) Propyne
c) But-1-yne
d) Pent-1-yne
Answer: b
Explanation: Propyne has many advantages and it is not as
hazardous as compared to the other fuels, so they are
used in rocket fuels.
123
Which among the following product is formed when
ethyne undergoes hydrogenation?
a) Formaldehyde
b) Formic acid
c) Acetaldehyde
d) Acetic acid
Answer: c
Explanation: When ethyne undergoes hydrogenation in
the presence of sulphuric acid, it forms ethanal.
124
Cycloalkanes have the same melting and boiling points
as their corresponding alkanes. State true or false
a) True
b) False
Answer: b
Explanation: The melting and boiling points of the
cycloalkanes are much more than the corresponding
alkanes
125
Identify the compound with the highest ring strain
a) Cyclomethane
b) Cyclopropane
c) Cyclobutane
d) Cyclopentane
Answer: b
Explanation: Cyclopropane is the compound with the
highest ring strain. This is because the carbon atoms are
arranged in the shape of a triangle thus forming C-C-C.
126
Which among the following compounds explodes on
contact with oxygen
a) Cyclopropane
b) Cyclobutane
c) Cyclopentane
d) Cyclohexane
Answer: a
Explanation: Cyclopropane reacts very aggressively at
ordinary temperatures and hence it explodes when comes
in contact with oxygen.
127
Identify the alicyclic hydrocarbon which is highly
flammable
a) Cycloheptane
b) Cyclopentane
c) Cyclopropane
d) Cyclooctane
Answer: b
Explanation: cyclopentane is a hydrocarbon with 5 carbon
atoms and they are highly flammable.
128
Alkadienes are classified into how many types?
a) 1
b) 2
c) 3
d) 4
Answer: c
Explanation: Based on the position and location of the
double bonds, they are classified into three types.
cumulative, conjugated, isolated dienes
129
Identify the one which is the perfect example for
Isolated double bond:
a) 1,4 pentadiene
b) 1,2 pentadiene
c) 1,3 pentadiene
d) 1,5 butadiene
Answer: a
Explanation: Only the 1,4 alkadiene compounds exhibit
isolated double bonds
129
A molecule in which more than one single bond
separates two double bonds are called as:
a) Coordinate bond
b) Isolated double bond
c) Cumulative double bond
d) Conjugated double bond
Answer: b
Explanation: As per the definition of isolation, a double
bond is separated by more than a single bond.
129
Conjugated diene reacts with which among the
following to form a cyclohexene
a) Phenol
b) Dienophile
c) Hexane
d) Tribromo phenol
Answer: b
Explanation: Dienophile on reaction with conjugated
dienes forms cyclohexene and this reaction is known as
Diels-alder reaction
130
Isolated dienes are similar in property to
a) Monoolefins
b) Diolefins
c) Triolefins
d) Tetraolefins
Answer: a
Explanation: Isolated dienes behave more like monoolefins
and have properties similar to them.
130
Identify the correct statement which is related to
aromatic hydrocarbon
a) It has only sigma bonds
b) It has only pi bonds
c) It has a sigma and two pi bonds
d) It has a sigma and delocalized pi bond
Answer: d
Explanation: An aromatic hydrocarbon always has a sigma
as well as a delocalized pi bond found between the carbon
atoms.
131
Which among these is the simplest example for
polycyclic arenes?
a) Benzacephenanthrylene
b) Naphthalene
c) Pyrene
d) Dibenz-anthracene
Answer: b
Explanation: Naphthalene has fused ring of aromaticity
and has the simplest structure when compared with other
polycyclic aromatic hydrocarbons.
132
Arenes are:
a) volatile
b) Water soluble
c) Non-carcinogenic
d) Mostly gases
Answer: a
Explanation: Arenes have a very low boiling point and
hence they are volatile in nature.
