Download IB2 SL CHEMISTRY Name: …………………………… Topic 10

IB2 SL CHEMISTRY
Name: ……………………………
Topic 10: Organic Chemistry
P1: …….. / 16p.
7: 37 
1.
3: 18 
2: 14 
Which products can be potentially obtained from crude oil and are economically important?
A.
B.
C.
D.
Plastics
Margarine
Motor fuel
I and II only
I and III only
II and III only
I, II and III
Which compound forms when hydrogen bromide is added to but-2-ene?
A.
B.
C.
D.
4.
4: 23 
Carbon monoxide and water
Carbon monoxide and hydrogen
Carbon dioxide and hydrogen
Carbon dioxide and water
I.
II.
III.
3.
5: 28 
Propane, C3H8, undergoes incomplete combustion in a limited amount of air. Which products are
most likely to be formed during this reaction?
A.
B.
C.
D.
2.
6: 32 
P2: ……. / 30p.
2-bromobutane
2,3-dibromobutane
1-bromobutane
1,2-dibromobutane
The following is a three-dimensional representation of an organic molecule.
1
Which statement is correct?
A.
B.
C.
D.
5.
Which statement about successive members of all homologous series is correct?
A.
B.
C.
D.
6.
The correct IUPAC name of the molecule is 2-methylpentane.
All the bond angles will be approximately 90°.
One isomer of this molecule is pentane.
The boiling point of this compound would be higher than that of pentane.
They have the same empirical formula.
They differ by a CH2 group.
They have the same physical properties.
They differ in their degree of unsaturation.
An organic compound X reacts with excess acidified potassium dichromate(VI) to form
compound Y, which reacts with sodium carbonate to produce CO2(g).
What is a possible formula for compound X?
A.
B.
C.
D.
7.
Which species reacts most readily with propane?
A.
B.
C.
D.
8.
Br2
Br•
Br–
Br+
Which compound is a tertiary halogenoalkane?
A.
B.
C.
D.
9.
CH3CH2COOH
CH3CH2CH2OH
CH3CH(OH)CH3
(CH3)3COH
(CH3CH2)2CHBr
CH3(CH2)3CH2Br
(CH3)2CHCH2CH2Br
CH3CH2C(CH3)2Br
What is the reaction type when (CH3)3CBr reacts with aqueous sodium hydroxide to form
(CH3)3COH and NaBr?
A.
B.
C.
D.
Addition
Elimination
SN1
SN2
2
10.
Which of the following products could be formed from the oxidation of ethanol?
I.
II.
III.
A.
B.
C.
D.
11.
I and II only
I and III only
II and III only
I, II and III
Which are characteristics typical of a free radical?
I.
II.
III.
A.
B.
C.
D.
12.
It has a lone pair of electrons.
It can be formed by the homolytic fission of a covalent bond.
It is uncharged.
I and II only
I and III only
II and III only
I, II and III
What is/are the product(s) of the reaction between ethene and hydrogen bromide?
A.
B.
C.
D.
13.
ethanal
ethanoic acid
ethane
CH3CH2Br
CH3CH2Br and H2
CH2BrCH2Br
CH3BrCH2 Br and H2
What is the correct name of this compound?
CH3
CH3
CH
CH2
CH 2
CH 3
A.
B.
C.
D.
14.
1,3-dimethylbutane
2,4-dimethylbutane
2-methylbutane
2-methylpentane
Which substance is not readily oxidized by acidified potassium dichromate(VI) solution?
A.
B.
C.
D.
propan-1-ol
propan-2-ol
propanal
propanone
3
15.
16.
Which reaction type is typical for halogenoalkanes?
A.
B.
C.
D.
nucleophilic substitution
electrophilic substitution
electrophilic addition
nucleophilic addition
(i)
Identify the formulas of the organic products, A–E, formed in the reactions, I–IV:


I.
II.
H
H
CH3(CH2)8OH + K2Cr2O7 
 A 
 B
(CH3)3CBr + NaOH 
 C
III.
IV.
H
(CH3)2CHOH + K2Cr2O7 
 D
H2C=CH2 + Br2 
 E

(5)
(ii)
H2C=CH2 can react to form a polymer. Name this type of polymer and draw the structural
formula of a section of this polymer consisting of three repeating units.
(2)
(Total 7 marks)
4
17.
(i)
State and explain the trend in the boiling points of the first six alkanes involving
straight-chains.
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(2)
(ii)
Write an equation for the reaction between methane and chlorine to form chloromethane.
Explain this reaction in terms of a free-radical mechanism.
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(5)
(Total 7 marks)
18. The following is a computer-generated representation of the molecule, methyl
2-hydroxy benzoate, better known as oil of wintergreen.
5
(i)
Deduce the empirical formula of methyl 2-hydroxy benzoate and draw the full structural
formula, including any multiple bonds that may be present.
The computer-generated representation shown does not distinguish between single and
multiple bonds.
(2)
(ii)
In this representation, two of the carbon-oxygen bond lengths shown are 0.1424 nm and
0.1373 nm. Explain why these are different and predict the carbon-oxygen bond length in
carbon dioxide.
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(2)
(iii) Name all the functional groups present in the molecule.
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(2)
(Total 6 marks)
19. (a)
List two characteristics of a homologous series.
.....................................................................................................................................
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.....................................................................................................................................
(1)
6
(b)
Ethanol and ethanoic acid can be distinguished by their melting points. State and explain
which of the two compounds will have a higher melting point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
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(2)
(c)
Draw the three isomers containing the alcohol functional group of formula C4H9OH.
(2)
(Total 5 marks)
20.
Secondary halogenoalkanes can undergo nucleophilic substitution reactions by both SN1 and SN2
mechanisms. The mechanism showing the formation of the transition state in the reaction
between 2-bromobutane and potassium hydroxide can be represented as follows.
CH 2 CH 3
H
(a)
C
Br
CH3
:OH –
CH 2 CH 3
H
HO
C
Br
CH
Identify the type of mechanism shown.
....................................................................................................................................
(1)
7
(b)
State and explain how the following changes would alter the rate of the reaction by this
mechanism.
(i)
using water instead of potassium hydroxide.
..........................................................................................................................
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..........................................................................................................................
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(2)
(ii)
using bromoethane instead of 2-bromobuture.
..........................................................................................................................
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..........................................................................................................................
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(2)
(Total 5 marks)
8
1.
A
[1]
2.
B
[1]
3.
A
[1]
4.
C
[1]
5.
B
[1]
6.
B
[1]
7.
B
[1]
8.
D
[1]
9.
C
[1]
10.
A
[1]
11.
C
[1]
12.
A
[1]
13.
D
[1]
14.
D
[1]
15.
A
[1]
16.
(i)
(ii)
A. = CH3(CH2)7CHO;
B. = CH3(CH2)7COOH/CH3(CH2)7CO2H;
C. = (CH3)3COH;
D. = (CH3)2CO;
E. = BrCH2CH2Br;
Allow correct structural formulas.
5
addition;
/-(CH2-CH2)3-/-(CH2)6-;
2
[7]
17.
(i)
boiling point increases as the number of carbons increases/OWTTE;
Greater Mr and hence greater van der Waals’/London/dispersion forces present;
2
9
(ii)
CH4 + Cl2
hv
/ UV
light

 CH3Cl + HCl;
Do not award mark if hv/uv light is not given.
Initiation step:
Cl2
hv
/ UV
light


2Cl•;
Do not award mark if hv/uv light is not given.
Penalize once only.
Propagation step:
CH4 + Cl• → CH3• + HCl;
CH3• + Cl2 → CH3Cl + Cl•;
Termination step:
Cl• + Cl•  Cl2 or Cl• + CH3•  CH3Cl or CH3• + CH3• → CH3CH3;
Allow fish-hook half-arrow representations i.e. use of
Penalize use of full curly arrows once only.
Penalize missing dots on radicals once only.
5
.
[7]
18.
(i)
(Empirical formula =) C8H8O3;
H
H
O
C
H
H
O
C
H
O
;
H
H
H
2
Allow double bonds on arene in alternate positions, or allow delocalized representation
(of pi electrons).
(ii)
(iii)
the bond at 0.1373 nm is a double bond and the bond at 0.1424 nm is a
single bond;
in CO2(g) both bonds are double bonds and would have a value
around 0.137 nm;
Ester;
Arene/benzene ring;
Alcohol;
Award 2 for any three correct, award [1] for any two correct.
Do not accept alkane as a type of functional group in this molecule.
2
2
[6]
19.
(a)
(b)
one general formula/same general formula;
differ by CH2;
similar chemical properties;
gradual change in physical properties;
Award [1] for any two of the above characteristics.
ethanol lower/ethanoic acid higher;
due to larger mass of ethanoic acid/stronger van der Waals’/
London/dispersion forces;
due to stronger hydrogen bonding/2 hydrogen bonds per molecule;
Accept either answer for second mark.
1
2
(c)
2
Allow condensed structural formulas such as CH3CH2CH2CH2OH.
Award [2] for all three correct isomers, [1] for any two correct isomers.
10
[5]
20.
(a)
SN2 / bimolecular;
(b)
(i)
(ii)
reaction slower;
neutral/uncharged/less polar/electrons donated less easily in H2O;
reaction faster;
less bulky group/reduced steric hindrance;
1
2
2
[5]
11