Question 1
The following statements are about the reaction of NaOH(aq) with the three chloroalkanes shown.
CH3CH2CHCl CH3 (CH3)2CHCH2Cl (CH3)3CCl
Which statement is correct?
(CH3)2CHCH2Cl reacts with NaOH(aq) by an SN2 mechanism
the tertiary chloroalkane reacts more quickly than the others because the carbon atom bonded to the Cl atom is more positive in this molecule
the Cl atoms in the three chloroalkanes are attacked by OH-
the molecular formula of the major product is C4H8 for each reaction
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Question 2
How many organic elimination products form when 2-bromobutane is heated with a concentrated solution of potassium hydroxide in ethanol?
1
2
3
4
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Question 3
Which of the following is a secondary halogenoalkane?
CH3CH2CHClCH3
(CH3)2CClCH3
CH2ClCH2CH2CH3
CH2ClCH2CH2CH2Cl
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Question 4
What is the mechanism and type of the reaction between ammonia and chloromethane?
electrophilic addition
nucleophilic addition
free radical substitution
nucleophilic substitution
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Question 5
An organic ion containing a carbon atom with a negative charge is called a carbanion.
An organic ion containing a carbon atom with a positive charge is called a carbocation.
The reaction between aqueous sodium hydroxide and 1-bromobutane proceeds by an SN2 mechanism.
What is the first step in the mechanism?
attack by a nucleophile on a carbon atom with a partial positive charge
heterolytic bond fission followed by attack by an electrophile on a carbanion
heterolytic bond fission followed by attack by a nucleophile on a carbocation
homolytic bond fission followed by attack by a nucleophile on a carbocation
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Question 6
Which radical is most likely to form by the homolytic fission of one covalent bond in bromochloromethane, CH2BrCl?
•CH2Cl
•CH2Br
•CHBrCl
•CH2BrCl
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Question 7
The formation of a carbocation from a halogenoalkane is an example of
homolytic fission
heterolytic fission
an initiation reaction
a propagation reaction
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Question 8
What describes the first step in the nucleophilic substitution reaction of ammonia with a halogenoalkane?
NH3 attacks the halogen atom
NH2- attacks the carbon atom next to the halogen
NH3 forms a bond with its lone pair to the carbon atom next to the halogen
the halogen atom is lost as a radical
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Question 9
Which statement correctly describes the boiling points of fluoroethane and iodoethane?
fluoroethane has the higher boiling point because it forms hydrogen bonds
fluoroethane has the higher boiling point because the C-F bond is stronger than C–I
iodoethane has the higher boiling point because it forms the stronger instantaneous dipole–induced dipole bonds
iodoethane has the higher boiling point because the C-I bond is less polar than C-F
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Question 10
When heated with NaOH(aq), 1-iodobutane is hydrolysed at amuch faster rate than 1-chlorobutane.
Which statement explains the different rates?
the C-I bond enthalpy is greater than the C-Cl bond enthalpy
the C-I bond is less polar than the C-Cl bond
the C-I bond has a C atom with a greater δ+ charge than in the C-Cl bond
the C-I bond requires less energy to break than the C-Cl bond
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Question 11
Which equation represents a termination step?
CH3CH2CH3 + Br• ➔ CH3CHCH3• + HBr
O3 + ClO• ➔ Cl• + 2O2
RO• + H2C=CH2 ➔ ROCH2CH2•
CH3CFCl• + Cl• ➔ CH3CFCl2
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Question 12
Why are fluoroalkanes unreactive?
fluorine is highly electronegative
the F- ion is very stable
they are polar molecules
the C-F bond is very strong
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Question 13
Which equation represents a propagation step?
•CH2Cl + Cl• ➔ CH2Cl2
•CH3 + •CH3 ➔ C2H6
Cl2 ➔ Cl• + Cl•
CH3Cl + Cl• ➔ •CH2Cl + HCl
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Question 14
Which equation represents an initiation step?
CH3CH2CHBr• + Br2 ➔ CH3CH2CHBr2 + Br•
O3 + Cl• ➔ O2 + ClO•
RCH2CH2• + H2C=CH2 ➔ RCH2CH2CH2CH2•
CH3CFCl2 ➔ CH3CFCl• + Cl•
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