Organic Chemistry
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Question 1
How many structural isomers are possible with the
molecular formula C6H14?
4
6
5
7
Wrong Answer!
Question 2
Which formulas represent butane or its isomer?
I. CH3 (CH2)2CH3
II. CH3CH (CH3)CH3
III. (CH3)3CH
I, II and III
I and III only
I and II only
II and III only
Wrong Answer!
All structures are valid and have the molecular formula
C4H10.
Question 3
Blur Professor Sim intends to create PVC through
polymerisation but does not know which
monomer to use. Which homogolous series
would be appropriate?
Alcohols
Carboxylic acids
Alkanes
Alkenes
Wrong Answer!
Alkenes and substituted alkenes readily undergo addition
reactions by breaking one of the double bonds. They can
be joined together to form polymers.
Question 4
Excess ethane was burnt in a closed system. Which of the
following is not a possible product?
Water
Carbon monoxide
Carbon dioxide
Soot
Wrong Answer!
Incomplete combustion of hydrocarbon produces carbon
monoxide, water and soot.
Question 5
What is the organic product of the reaction
between ethanol and ethanoic acid in the
presence of concentrated sulfuric acid?
CH3CHO
CH3COOCH3
CH3CH2COOCH3
CH3COOCH2CH3
Wrong Answer!
The product is an ester, ethyl ethanoate.
Question 6
Which compound is a member of the aldehyde
homologous series?
CH3CH2COCH3
CH3CH2CHO
CH3CH2CH2COH
CH3CH2COOH
Wrong Answer!
Aldehydes contain the –CHO functional group.
Question 7
What type of alcohol is 2-methylpropan-2-ol?
an unsaturated
alcohol
a tertiary alcohol
a secondary alcohol
a primary alcohol
Wrong Answer!
It is a tertiary alcohol, C(CH3)3 or CH3C(CH3)2-OH
Question 8
Which of the following descriptions can be correctly applied
to the homologous series of alkanes?
I. Members of the series have the general formula CnH2n+2
II. Members of the series have similar chemical properties.
III. Members of the series are isomers of each other.
I only
II only
I and II only
I and III only
Wrong Answer!
The members of a homologous series are not isomers of
each other, other statements are correct.
Question 9
Which compound is an ester?
CH3CH2COOH
C2H5OC2H5
C3H7CHO
HCOOCH3
Wrong Answer!
It contains an ester linkage: -COO-
Question 10
Which one of the following is the best method of
distinguishing between an alkane and alkene?
Test with universal
indicator
Burn the gases in
excess oxygen
Test their solubility
in water
Add bromine water
Wrong Answer!
Alkenes rapidly react with bromine water via addition
reaction.
Question 11
What is the name of the compound whose
condensed structural formula is
CH3CH2CH2COOCH3?
butyl methanoate
methyl butanoate
methyl propanoate
pentanone
Wrong Answer!
The compound is an ester formed from butanoic acid
(see first part of the structure) and methanol (see seoncd
part of the structure); therefore it is methyl butanoate.
Question 12
A gaseous hydrocarbon, X, decolorizes aqueous
bromine.Which one of the following molecular
formulas could be X?
C2H4
C6H14
C13H28
C10H20
Wrong Answer!
C6H14 and C13H28 are both alkanes, C2H4 and C10H20 are
both alkenes, but only C2H4 is a gas at room
temperature.
Question 13
What is the function of sunlight during the reaction
between chlorine and methane?
To dissociate the
chlorine molecules
into atoms.
To dissociate the
chlorine molecules
into ions
To increase the
temperature of the
mixture.
To break the C-H
bonds in the methane
molecule.
Wrong Answer!
Light is a form of energy and is absorbed by chlorine
molecules to dissociate the covalanet bond between the
two chloribe atoms. Homolytic fission occurs:
Cl2(g)  2Cl  (g)
Question 14
What is the IUPAC name for (CH3)2C(OH) CH2CH3?
pentan-3-ol
2-methylbutan-2-ol
3-methylbutan-3-ol
4-methylbutan-3-ol
Wrong Answer!
There are 4 carbon atoms in the longest unbranched
chain. There is a methyl group and an –OH group on the
second carbon atom.
Question 15
How do the bond angles and bond lengths in ethane and
ethene compare?
H-C-H bond
C-C bond
angle in ethane
length in ethane
larger
longer
smaller
longer
smaller
shorter
larger
shorter
Wrong Answer!
The bond angle in ethane is smaller, 109.50 compared to
1200 , bond length in ethane is longer as the bond is just
a single C-C bond, whereas there is a C=C bond in
ethene.
Question 16
Which equation represents the combustion of
methane in excess oxygen?
CH4(g) + O2(g)
C(s)+2H2O(g)
CH4(g) + O2(g)
CO2 (g)+2H2(g)
2CH4(g) + 3O2(g)
2CO (g)+4H2O(g)
CH4(g) + 2O2(g)
CO2 (g)+2H2O(g)
Wrong Answer!
Carbon dioxide and water are formed by complete
combustion of a hydrocarbon.
Question 17
When the compounds below are listed in order of
decreasing boiling point (highest to lowest) what is the
correct order?
1. ethane
2. chloroethane
3. ethanol
4. ethanoic acid
2, 1, 3, 4
4, 3, 2, 1
4, 3, 1, 2
3, 4, 1, 2
Wrong Answer!
Ethanoic acid and ethanol form stronger hydrogen bond,
chloroethane and ethane molecules are bonded by weak van der
Waals forces.
Stronger bonds -> Higher boiling point since greater amount of
energy is needed to break the bonds.
The order of bond stength is
Ethanoic acid > ethanol > chloroethane > ethane
Hydrogen bonds ------------------------van der Waals forces
Question 18
The compound which is expected to have the
lowest boiling point at a pressure of one
atmosphere is:
CH3CH2CH2F
CH3CH2COOH
CH3CH2CH2OH
CH3CH2CH2NH2
Wrong Answer!
The molecules will only have van der Waals’ forces
acting between them, other examples have the capbility
of hydrogen bonding between the molecules.
Question 19
Which products can be potentially obtained from crude oil
and are economically important?
I. Plastics
II. Margarine
III. Motor fuel
I and II only
I and III only
II and III only
I, II and III
Wrong Answer!
Question 20
Which statement is correct about the reaction
between methane and chlorine?
It involves heterolytic
fission and Cl  radicals
It involves homolytic
fission and Cl  radicals
It involves heterolytic

fission and Cl ions
It involves homolytic

fission and Cl ions
Wrong Answer!
The bond between the 2 chlorine atoms in Cl2 is
weaker than C-H or C-C bond in CH4 and can break
homolytically in the presence of UV to form 2 free Cl
radicals.
Question 21
Which product is formed when hydrogen chloride
is added to but-2-ene?
2-chlorobutane
2,3-dichlorobutane
1-chlorobutane
1,2-dichlorobutane
Wrong Answer!
Cl
H
HCl + H3C-C = C-CH3 H3C – C – C – CH3
H
H
H
H
Question 22
The oxidation of propan-2-ol, CH3CH(OH)CH3, by
sodium dichromate(VI) leads to the formation of:
Propanone,
CH3COCH3
Propan-1-ol,
CH3CH2 CH2 OH
Propanal,
CH3CH2CHO
Propanoic acid,
CH3CH2 CO2H
Wrong Answer!
Oxidation of secondary alcohol forms a ketone.
Congratulations!