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WorksheetsPreliminary Exam in Organic Chemistry
Total questions: 90
Worksheet time: 1hrs 2mins
Organic compounds made only of the elements carbon and hydrogen are called...
Hydrocarbons
Carbohydrogens
Carbohydrates
Hydrocarbonates
Which one of the following characteristics is not TRUE for all of the members of the same homologous series?
They have the same general formula.
They have similar chemical properties, i.e. undergo the same reactions.
They have varying physical properties, i.e. change in a predictable way.
They have different functional group.
Arrange the following alkanes in increasing number of carbon atoms.
methane, ethane, propane, butane
ethane, methane, propane, butane
methane, ethane, butane, propane
methane, propane, ethane, butane
Which type of bonding is present within organic molecules?
Covalent bond
Ionic bond
Metallic bond
Hydrogen bond
Which list does NOT contain compounds found in the same homologous series?
methane, ethane, propane, butane
Pentane, hexanol, heptane, octane
nonane, decane, undecane, dodecane
tridecane, tetradecane, pentadecane, hexadecane
Which of the following is NOT TRUE regarding isomerism?
They differ in both physical and chemical properties
They have different molecular formula
There are two types of isomerism : Structural and Stereoisomerism
Geometric and optical isomerism are two types of stereoisomerism
Isomerism that arises out of the difference in spatial arrangement of atoms or groups about the doubly bonded carbon atoms are called?
Structural Isomerism
Stereoisomerism
Geometrical Isomerism
Optical Isomerism
Which among the following does not exhibit geometric isomerism?
1-hexene
2-hexene
3-hexene
4-hexene
The molecular formula C5H12 contains how many isomeric alkanes?
1
2
3
4
Which of the following is NOT true about nucleophiles?
donates an electron pair to an electrophile to form a chemical bond
all molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles
nucleophile are Lewis acids by definition
a nucleophile becomes attracted to a full or partial positive charge
What is a functional group?
Atoms or group of atoms that give specific characteristics to a molecule
Group of molecules that make up a group of atoms
Group of molecules that give specific characteristics to an atom
Group of atoms that give specific characteristics to an element
Classify the compound based on the functional group present.
Ketone
Carboxylic acid
Ester
Ether
Classify the compound based on the functional group present.
Ether
Ketone
Ester
Carboxylic acid
Which statement best defines chain isomerism?
Existance of chemical compounds with same molecular formula
Different ways the same number of carbons are connected which is either straight or branched
Have mirror image of each other
Similar chemical properties with different physical properties such as solubility
How to determine that a molecule exhibit cis-trans isomerism?
Restricted rotation in a carbon-carbon single bond of alkenes
Each carbon of a site of restricted rotation has 2 different atoms or groups attached to it
Exist in cyclic compouds only
Similar chemical properties
Which of the following molecules exhibit geometrical isomerism?
CH2=CHCH3
C6H5CH=CHC6H5
(CH3)2C=CHCH3
CH3CH2N=OH
Formation of a single product from two reactant molecules is known as:
addition reaction
substitution reaction
elimination reaction
oxidation reaction
What is the name of the process in which one orbital "S" and three orbitals "P" combined to form new orbitals?
Combining
Joining
Hybridization
Hydrozation
In hydrocarbons, how does the rate of carbon and hydrogen increase?
C: 1 H: 2
C:2 H: 1
C:1 H: 3
C.0 H: 1
What technique is used to separate crude oil (Petroleum) into its different fragments?
Evaporation to dryness
Separating funnel
Simple distillation
Fractional distillation
What is the main constituent of Natural Gas?
Ethene
Helium
Hydrogen
Methane
Why is methane used as a fuel?
It burns and releases energy.
.It is a gas.
It is odourless.
It has a low boiling point.
Which fraction is used as a fuel for aircraft engines?
H
I
J
K
How many hydrogens are missing from this extended structural formula?
6
7
8
9
How many single covalent bonds does benzene (C6H6) molecule have?
3
6
9
12
This type of bond allows free rotation of the parts of the molecule with respect to each other.
Sigma bond
Pi bond
Covalent bond
Electron bond
Which type of bond is weaker and is more prone to chemical attacks?
Pi bond
Sigma bond
This is a region about the nucleus where the probability of finding the electrons is very high.
Pi bond
Atomic orbital
Sigma bond
Hybrid orbital
A homologous series is a family of organic compounds with:
similar chemical properties and same general formula
similar chemical properties and different general formula
different chemical properties and same general formula
similar physical properties and same general formula
Which of the following statements concerning organic compounds is correct?
Organic compounds are found only in non-living systems.
Organic compounds are always soluble in water.
Organic compounds cannot be found in nature; they must be synthesized in a laboratory.
Organic compounds always contain the element carbon.
The distinction between a saturated hydrocarbon and an unsaturated hydrocarbon relates to:
boiling points
volatility
number of Carbon atoms present
the number of multiple bonds present in the molecule
The four hydrogen atoms bonded to the central carbon atom in methane lie at the corners or apexes of a:
rectangle
tetrahedron
square
parallelogram
Which of the following could not be the molecular formula for an alkane molecule?
C4H10
C5H14
CH4
C24H50
The representation CH3CH2CH3 for the alkane propane is an example of:
a molecular formula
a condensed structural formula
an expanded structural formula
a skeletal structural formula
Constitutional isomerism is possible in alkanes only if the number of carbon atoms present is:
four or more
five or more
an even number
an odd number
In which of the following pairs of alkanes are the two members of the pair constitutional isomers?
hexane and 3-methylhexane
2,4-dimethylhexane and 2,4-dimethylheptane
ethane and propane
3-methylnonane and 3,4-dimethyloctane
The minimum number of carbon atoms required to form a branched-chain alkane and a branched-chain alkyl group are, respectively,
three and three
four and four
three and four
four and three
When the molecular formulas for cyclic and noncyclic alkanes with the same number of carbon atoms are compared, it is always found that the cycloalkane has:
two more hydrogen atoms.
the same number of hydrogen atoms.
c.
two less hydrogen atoms.
four less hydrogen atoms.
Which of the following is an incorrect IUPAC name for a cycloalkane?
cyclobutane
propylcyclopentane
1,2-dimethylcyclopentane
3,3-cyclopentane
For which of the following cycloalkanes is cis-trans isomerism possible?
isopropylcyclopropane
propylcyclobutane
1-methyl-1-propylcyclopropane
1-ethyl-2-methylcyclodecane
Which of the following is a general physical property of alkanes?
Low solubility in water.
Less volatile than water.
More dense than water.
More polar than water.
The most important chemical use for alkanes relates to their chemical reaction with:
hydrogen
oxygen
chlorine
bromine
What is the common name for the halogenated hydrocarbon whose IUPAC name is 2-chloropropane?
sec-propyl chloride
ethyl chloride
propyl chloride
isopropyl chloride
The number of constitutional isomers possible for alkanes of a given molecular formula______
is the same as the number of hydrogen atoms present
is double the number of carbon atoms present
cannot be calculated in a simple way from the molecular formula
No correct response
Which of the following compounds is a constitutional isomer of CH3CH2CH2CH2CH3?
2-methylpentane
2-methylbutane
2,2-dimethylbutane
pentane
Which of the following statements concerning the boiling points of specific alkanes is correct?
Hexane has a higher boiling point than heptane.
Pentane has a higher boiling point than 2-methylpentane.
Butane has a higher boiling point than cyclobutane.
No correct response.
Which of the following is a correct pairing of common and IUPAC names for halogenated hydrocarbons?
ethyl chloride and dichloromethane
isopropyl chloride and 1-chloropropane
tert-butyl chloride and 2-chloro-2-methylpropane
No correct response
Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
(1) Alkanes have limited solubility in water and are less dense than water.
(2) Propane is an alkane in which both 1o and 2o carbon atoms are present.
(3) Some, but not all cycloalkanes, can exist is cis-trans isomeric forms.
All statements are true.
Two of the three statements are true.
Only one of the statements is true.
None of the statements is true.
Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
(1) A minimum of four carbon atoms is required in a cycloalkane.
(2) The molecules 2,4-dimethylpentane and 2,4-dimethylhexane are constitutional isomers.
(3) As a result of rotation about single bonds, all alkane molecules, except methane, can exist in an infinite number of conformations.
All three statements are true.
Two of the three statements are true.
Only one of the statements is true.
None of the statements is true.
The common feature found in all unsaturated hydrocarbons is:
one or more carbon-carbon double bonds
one or more carbon-carbon triple bonds
one or more carbon-carbon multiple bonds
one or more rings of carbon atoms
A cycloalkene having only one carbon-carbon double bond will have the general formula:
CnH2n+2
CnH2n
CnH2n-2
CnH2n-4
The bond angles associated with a carbon-carbon double bond in an alkene are:
180°
120°
109°
90°
Cis-trans isomerism is possible for which of the following alkenes?
CH2=CH–CH2–CH2–CH3
CH3–CH=CH–CH2–CH3
CH3–CH=CH2
CH2=CH–CH2–CH3
The correct IUPAC name for CH2=CH–CH=CH2 is
1,4-butene
1,3-butadiene
1,3-dibutene
1,4-dibutene
Which of the following reactants can be used to convert an alkene to an alkane?
H2
Cl2
HCl
H2O
Markovnikov's rule is needed to predict the product in the reaction between HCl and:
CH2=CH2
CH3–CH=CH–CH3
CH2=CH–CH3
CH3–CH3
Which of the following addition polymers contains only carbon and hydrogen?
polystyrene
PVC
Teflon
Saran
Which of the following alkynes goes by the common name of acetylene?
ethyne
propyne
1-butyne
2-butyne
How many units of unsaturation are there in the following compound:
1
2
3
4
The geometric isomers shown below is called:
Which of the following will have higher melting point?
cis –But-2-ene
trans –But-2-ene
The following compound has a ______________ orientation.
cis
trans
Which of the following does not exist as a liquid at room temperature?
but-1-ene
pent-1-ene
hex-1-ene
hep-1-ene
As the number of Carbon atoms increases in a straight chain of alkene or alkynes, the boiling point ________________.
increases
decreases
remains the same
The forces of attraction between alkene molecules are due to weak forces known as
Van der waal's forces of attraction
London Forces of attraction
Hydrogen Bond
Ion-dipole Interaction
In gengeneral, Alkenes are:
polar
nonpolar
True or False: Alkenes can be dissolved in gasoline.
True
False
True or False: Pentene will conduct electricity.
True
False
Which of the following has longer bond lengths?
Double
Single
Triple
All the Same
If Double bonds are stronger, why are they more reactive?
Sigma bonds aren't as strong as Pi bonds
They aren't more reactive.
Pi bonds aren't as strong as sigma bonds
More bonds to react with things
How many Pi Bonds are there in Ethyne?
1
2
3
4
Name this compound.
3-methyl-1,5-hexene
4-methyl-1,4-hexadiene
3-methyl-dihexene
3-methyl-1,5-hexadiene
Name this compound
1,5,5-trimethyl-1,3-cyclohexadiene
1,4,4-trimethyl-1,3-cyclohexadiene
1,5,5-trimethyl-1,3-cyclohexiene
5,1,1-trimethyl-1,3-cyclohexadiene
Name this compound
cis-trans-2,4-octadiene
cis-cis-2,4-octadiene
trans-trans-2,4-octadiene
trans-cis-2,4-octadiene
If you react Octene with Hydrogen, using heat and Ni as a catalyst, what is the product?
Octyne
Octane
Heptadiene
Propene
Hydration of an alkene with acid produces what?
alcohol
alkyne
diene
carboxylic acid
Name the compound.
1-bromo-2-chloro-5-octyne
8-chloro-1-bromo-4-octyne
1-bromo-8-chloro-4-octyne
Is this an explosive compound?
Yes
No
Name the compound.
2,4-dibromobenzene
dibromo-hexatriene
1,2-dibromobenzene
1,2-dibromo-3-hexatriene
Name this compound
2-methylpent-2-ene
hex-2-ene
2-methylpent-3-ene
4-methylpent-3-ene
hex-3-ene
Name this compound.
2-methylhept-3-yne
2-methylhept-4-yne
6-methylhept-3-yne
oct-3-yne
hept-3-yne
The basic unit for the terpene is the isoprene unit.
True
False
Which of the following statements is TRUE of Terpenes?
Soluble in organic solvent and usually insoluble in water
Insoluble in organic solvent and usually soluble in water
Soluble in organic solvent and always soluble in water
Insoluble in organic solvent and insoluble in water
Limonene has a ________ aroma.
Floral
Pepper
Cloves
Citrus
Which of the following is NOT true about pheromones?
Chemical that an animal produces which changes the behavior of another animal of the same species.
Behavior-altering agents.
Work internally.
Are endohormones.
Fruits and other vegetables contain terpenes.
True
False
Zingiberine contains beta-carotene.
True
False
Oils are partially hydrogenated and contains low molecular weight fatty acid called:
oleic acid
linolenic acid
lauric acid
citric acid
Hydrohalogenation requires the presence of catalyst during the chemical reaction.
True
False
