Download Topic 11 Organic Chemistry

Topic 10
Organic Chemistry
10.1
Functional Groups and Isomerism SL/HL
1.Which of the following pairs represent members of an homologous series?
A.
C2H4 and C2H6
B.
C2H5Cl and C2H4Cl2
C.
CH3OCH3 and CH3CH2OH
D.
C3H7COOH and C4H9COOH
2. Which names are correct for the following isomers of C6H14?
2-methylpentane
2ethyl-2-methylpropane
2,3-dimethylbutane
A.
I only
B.
I and II only
C.
I and III only
D.
I,II and III
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3. Which compound is a member of the same homologous series as 1-chloropropane?
A.
1-chloropropene
B.
1-chlorobutane
C.
1-bromopropane
D.
1,1-dichloropropane
4. Which formula represents an amide?
A.
CH3CH2NH2
B.
CH3CH2N(CH3)2
C.
H2NCH2CO2H
D.
CH3CONH2
5. Which of the following is an amine?
A.
CH3CH2NH2
B.
CH3CONH2
C.
-[CH2CONHCH2CO]n_
D.
CH3CH2C ≡ N
6. How many different structural isomers have the formula C4H9C1?
A.
2
B.
3
C.
4
D.
5
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7.
How many different isomers have the formula C4H10 ?
A.
1
B.
2
C.
3
D.
4
8.
9. The alkanes are a homologous series of saturated hydrocarbons.
(a) State the meaning of each of the following terms.
(i)
homologous series
[1]
(ii) saturated
(b) (i)
[1]
State and explain the trend in the boiling points of the first five alkanes.
[2]
(ii) Give the structural formulas for the isomers of molecular formula C4 H10 and state the
name of each one
[2]
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10. (i)
group.
List three characteristics of an homologous series, and explain the term functional
[3]
(ii) Draw the four structures of alcohols of formula C 4H9OH. Name each one and
label them as either primary, secondary or tertiary alcohols.
[4]
(iii) Many organic compounds can exist as isomers. Draw and name an isomer of ethanoic
acid,
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[2]
Topic 10
Organic Chemistry
10.2
Physical Properties of Organic Compounds
SL/HL
1. When the compounds below are listed in order of decreasing boiling point (highest to lowest) what is the
correct order?
1.
ethane
A.
4,3,1,2
B.
4,3,2,1
C.
3,4,1,2
D.
2,1,3,4
2.
fluoroethane
3.
2. Which of the following is expected to be a gas at 25° C?
3.
Which compound is the most soluble in water?
A.
Methane
B
Propane
C.
Propan-1-ol
D.
Pentan-1-ol
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ethanol
4.
ethanoic acid
4. Statement (S): Solubility of alcohols in water decreases with increase in Mr.
Explanation (E): The relative proportion of the hydrocarbon part in alcohol increases with increasing Mr.
A.
Both S and E are true.
B.
Both S and E are false.
C.
S is true but E is false.
D.
S is false but E is true.
5. Explain why the boiling points of ethanol and ethanoic acid are considerably higher than the
boiling point of ethanal.
[3]
6.
Discuss the factors which affect the boiling points of covalently bonded compounds by reference to
the following pairs of organic substances, whose boiling points are given:
• ethane (184 K) and butane (273 K);
• ethane ( 184 K) and bromoethane (311 K);
• bromoethane (311 K) and ethanol (352 K).
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[6]
Topic 10
Organic Chemistry
10.3
Reactions of Alkanes and Alkenes
SL/HL
1. Which statement is correct about the reaction between methane and chlorine?
A.
It involves heterolytic fission and ions. Cl−
B.
It involves heterolytic fission and Cl* radicals.
C.
It involves homolytic fission and ions. Cl−
D.
It involves homolytic fission and Cl * radicals.
2. Which are characteristics typical of a free radical?
I. It has a lone pair of electrons.
II. It can be formed by the homolytic fission of a covalent bond.
III. It is uncharged.
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
3. Which is the best description of the following reaction?
C2H4 + H2O → C2H5OH
A.
Addition
B.
Condensation
C.
Dehydration
D.
Hydrogenation
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4. Which chemical is most likely to be a starting material for a common polymer?
A.
CH3CH2CH3
B.
CH3CH2OH
C.
CH3CHCH2
D.
5. What will be formed when CH2 = CH2 reacts with Br2 in the dark?
A.
CH2Br —CH2Br
B.
CH3—CHBr2
C.
CH 2 =CHBr + HBr
D.
CHBr = CHBr + H 2
6. (a) Describe a chemical test to distinguish between alkanes and alkenes, giving the result in each
case. [2]
(b) Name the type of polymerization reaction which C3H6 undergoes and draw the structure of a section
of the polymer chain formed from three monomer molecules.
[3]
7. Give an equation for the complete combustion of methane, CH 4. Identify two products formed by
the incomplete combustion of methane and identify one harmful effect caused by one of the products.
[4]
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8. The plastic PVC, poly(chloroethene), is made from the monomer chloroethene, C2H3C1, by a
polymerization reaction.
(i)
Draw the structural formula of chloroethene.
(ii)
State the type of polymerization reaction that occurs to make poly(chloroethene) and
[1]
identify the structural feature needed in the monomer.
[2]
(iii) Draw the structure of the repeating unit of poly (chloroethene).
[1]
(iv) Explain why monomers are often gases or volatile liquids, whereas polymers are solids.
[2]
9. Alkanes are often described as having low reactivity, although they do react with halogens.
(i)
Explain why alkanes are unreactive.
[2]
(ii) The first step in the reaction of propane with bromine can be represented by the equation.
Br2→ 2Br∙
State the type of species formed in this step and name the type of bond fission.
[2]
10. Under certain conditions ethene can be converted to ethanol.
(i)
Give a chemical test to identify ethene and state what would be observed.
(ii) Give a balanced equation for the reaction to form ethanol from ethene.
(iii) State the conditions necessary for the reaction in (ii).
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[4]
Topic 10
Organic Chemistry
10.4
Reactions of Alcohols
SL/HL
1. Which compound is converted to butanal by acidified potassium dichromate(VI) solution?
A.
butan-1-ol
B.
butan-2-ol
C.
butanone
D.
butanoic acid
2. What is the final product formed when ethanol, CH3CH2OH is reacted with acidified potassium dichromate(VI)?
A.
ethanal
B.
ethane
C.
ethanoic acid
D.
ethene
3. Which compound will undergo oxidation when treated with acidified potassium dichromate(VI)?
A.
CH3CH2CHO
B.
CH3COCH3
C.
CH3COOH
D.
(CH3)3COH
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4. (a) Propan-1-ol, in the presence of a small amount of oxidising agent, forms compound X,
and when refluxed with an excess of oxidising agent, forms compound Y.
(i)
Identify a suitable oxidising agent and state the colour change.
[2]
(ii) Draw the structural formulas of both compound X and compound Y.
[2]
(b) Some alcohols are oxidized by heating with acidified potassium dichromate(VI). If oxidation
does occur, identify the possible oxidation products formed by each of the alcohols below.
Indicate if no oxidation occurs.
Butan–1–ol
Butan–2–ol
2–methylpropan–2–ol
5. This question is concerned with compounds having the molecular formula C3H8O.
(a)
Draw the full structural formulas of the three possible isomers and give the name of each.
[5]
(b)
Predict how each of these isomers would behave when reacted with limited (i.e. not in
excess) acidified potassium dichromate(VI) solution and describe any observation that
could be made. Write the structures of any organic products formed and give their names.
[6]
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[4]
Topic 10
Organic Chemistry
10.5
Reactions of Halogenoalkanes
SL/HL
1. The reaction between 1-bromopropane and warm dilute sodium hydroxide solution is described as an
SN 2 nucleophilic substitution reaction.
(i)
Explain each of the terms in SN 2.
[3]
(ii) Write an equation and a mechanism for the reaction.
[5]
2. (i) 1-bromopropane is described as a primary halogenoalkane and 2-bromopropane is
described as a secondary halogenoalkane. Explain these terms with reference to the
two examples given.
[2]
(ii) Give the structural formula of a tertiary halogenoalkane.
[1]
(iii) State the type of substitution reaction undergone by tertiary halogenoalkanes.
[1]
3. Give the structural formulas of the four isomers of molecular formula C4H9Cl. State the
name of each one and classify it as primary, secondary, or tertiary.
[8]
(b) Each of the isomers reacts with aqueous sodium hydroxide. State what class of compound is
produced by this reaction.
[1]
(c) (i) Identify the type of isomer (primary, secondary or tertiary) which will react with
aqueous sodium hydroxide almost exclusively by an SN1 mechanism. State the
meaning of the symbols in the term SN1 mechanism.
[2]
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Topic 10
Organic Chemistry
10.6
Reaction Pathways
SL/HL
1. This question refers to the compounds in the following reaction scheme.
Na0H
C3H7Br →
C3H8O→0xidation C3H6O
A
B
C
0xidation
→ C3H6O2
D
(a) State a suitable reagent for the oxidation of B to C and C to D. Explain how the oxidation
of B to C could be achieved without further oxidation to D. [3]
(b) The conversion of A to B takes place by an SN 2 mechanism. State what is meant by the
term SN2 and describe, by using "curly arrows" to show the movement of electron pairs, the
mechanism of this conversion.
[6]
2. This question is about four compounds A, B, C and D, which can be made from ethene by
the following reactions. All four compounds are liquid at room temperature, and each
compound's molecular formula is shown.
(a)
C2H4
C2H6O
A
B
C2H4O
C
C2H4O2
D
Use the information above to identify each of the compounds A, B, C and D giving the
name and structural formula of each one.
[8]
(b) State the type of reaction occurring when A is converted to B and state the reagent required.
[2]
(c) Compound A can react with bromine. Write an equation for this reaction and
name the product. State a visible change which accompanies the reaction.
[3]
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