11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.

com

Paper 3
Questions are applicable for both core and extended candidates

1 The structures of seven compounds, A, B, C, D, E, F and G, are shown.

A B C D
H H H H H O
S
C C C H C C C
O O
H H
H H H H H O H

E F G
H H H H H

H C C O H H C C C H O C O

H H H H H

Answer the following questions about these structures.

Each structure may be used once, more than once or not at all.

(a) State which structure, A, B, C, D, E, F or G, represents:

(iv) a carboxylic acid

....................................................................................................................................... [1]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 4
Questions are applicable for both core and extended candidates
unless indicated in the question

2 Carboxylic acids can be converted into esters.

(a) Propanoic acid and methanol react to form an ester that has the molecular formula C4H8O2.

(i) Name this ester and draw its displayed formula. (extended only)

name of ester ....................................................................................................................

displayed formula

[2]

(ii) Name another ester with the molecular formula C4H8O2. (extended only)

...................................................................................................................................... [1]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

3 The names of four esters are listed.

methyl propanoate
ethyl propanoate
propyl propanoate
butyl propanoate

(a) Esters are a family of organic compounds with similar chemical properties. They can be
represented by the formula CnH2nO2.

(i) State the name given to a family of organic compounds with similar chemical properties.

....................................................................................................................................... [1]

(ii) Explain why members of a family of organic compounds have similar chemical properties.

....................................................................................................................................... [1]

(iii) State the name given to a formula such as CnH2nO2.

....................................................................................................................................... [1]

(iv) Determine the value of ‘n’ in butyl propanoate.

....................................................................................................................................... [1]

(b) All four of the esters in the list are liquids at room temperature.

Name the technique used to separate ethyl propanoate from a mixture of the four esters.

.............................................................................................................................................. [2]

(c) All four esters can be made by reacting different alcohols with the same substance.

(i) Name this substance and draw its structure. Show all of the atoms and all of the bonds.

name ....................................................... (extended only)

structure

[2]

(ii) Name the alcohol used to make methyl propanoate. (extended only)

....................................................................................................................................... [1]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

(d) Other esters, not in the list, have the same molecular formula as propyl propanoate, but different
structures.

(i) State the term used to describe substances with the same molecular formula but different
structures.

....................................................................................................................................... [1]

(ii) Name two esters with the same molecular formula as propyl propanoate. (extended only)

1 ..........................................................................................................................................

2 ..........................................................................................................................................
[2]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

4 Ethanoic acid is manufactured by the reaction of methanol with carbon monoxide.

(e) Ethanoic acid is a member of the homologous series of carboxylic acids.

State the general formula of this homologous series.

.............................................................................................................................................. [1]

(f) Draw the structure of the carboxylic acid containing three carbon atoms. Show all of the atoms
and all of the bonds. (extended only)

[2]

(g) When carboxylic acids react with alcohols, esters are produced.

The formula of ester X is CH3CH2CH2COOCH3.

(i) Name ester X. (extended only)

....................................................................................................................................... [1]

(ii) Give the name of the carboxylic acid and the alcohol that react together to produce ester X.
(extended only)

carboxylic acid ....................................................................................................................

alcohol ................................................................................................................................
[2]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

5 Ester Y has the structure shown.

O H

H C O C H

(a) (i) Name ester Y. (extended only)

....................................................................................................................................... [1]

(ii) Deduce the empirical formula of ester Y.

....................................................................................................................................... [1]

(b) Complete the dot-and-cross diagram to show the arrangement of electrons in a molecule of
ester Y.

O
H

H C O C H

[3]
11.2 Naming organic compounds QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

(c) Ester Y can be made by reacting two organic compounds together.

Name the compounds and draw their structures. (extended only)

Show all of the atoms and all of the bonds.

name ..............................................................

structure

name ..............................................................

structure

[4]

(d) (i) Describe what is meant by the term structural isomer.

.............................................................................................................................................

....................................................................................................................................... [2]

(ii) Name a carboxylic acid which is a structural isomer of ester Y. (extended only)

....................................................................................................................................... [1]

[Total: 12]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 3
Questions are applicable for both core and extended candidates

1 Table 2.1 shows the masses of some of the ions in a 1000 cm3 sample of river water.

Table 2.1

mass of ion in 1000 cm3

name of ion formula of ion
of river water / mg
NH4+ 0.4
calcium Ca2+ 1.4
chloride Cl – 0.1
hydrogencarbonate HCO3– 1.2
magnesium Mg2+ 0.6
nitrate NO3– 0.8
phosphate PO43– 1.3
sodium Na+ 0.5
SO42– 0.4

(e) River water can contain acids such as ethanoic acid and methylbutanoic acid.

(i) Draw the displayed formula for ethanoic acid.

[1]

(ii) Ethanoic acid reacts with sodium hydroxide.

Complete the word equation for this reaction.

ethanoic sodium ........................ ........................

+ → +
acid hydroxide
........................

[2]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

2 (a) Fig. 7.1 shows the displayed formula of compound S.

H

H C O H

H C H

C
O O H

Fig. 7.1

(i) On Fig. 7.1, draw a circle around the carboxylic acid functional group. [1]

(ii) Deduce the molecular formula of compound S.

....................................................................................................................................... [1]

(c) Ethanoic acid is a carboxylic acid.

Complete the word equation for the reaction of ethanoic acid with sodium hydroxide.

ethanoic sodium ........................ ........................

+ → +
acid hydroxide
........................
[2]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

3 Toothpaste contains cinnamal. The structure of cinnamal is shown.

H H

C C H H

H C C C C C
C C H O
H H

(d) Cinnamal can be oxidised to a carboxylic acid.

(i) Draw the structure of a carboxylic acid functional group to show all of the atoms and all of
the bonds.

[1]

(ii) Ethanoic acid is a carboxylic acid.

Ethanoic acid reacts like a typical acid.

Complete the word equation for the reaction of ethanoic acid with sodium carbonate.

ethanoic sodium sodium ........................ ........................

+ + +
acid carbonate ethanoate
........................

[2]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 4
Questions are applicable for both core and extended candidates
unless indicated in the question

4 The equation for the reaction between methanoic acid and ethanol in the presence of a catalyst can
be represented as shown.

HCOOH + CH3CH2OH X + H2O ∆H = –29.5 kJ / mol

X represents the ester formed.

(a) (i) In the equation, methanoic acid is represented by the formula HCOOH.

Name this type of formula.

....................................................................................................................................... [1]

(ii) Write the empirical formula of methanoic acid.

....................................................................................................................................... [1]

(b) Name and draw the displayed formula of ester X. (extended only)

name .................................................................

displayed formula

[3]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

5 Propane, propene, propan-1-ol and propanoic acid are members of different homologous series.

Molecules of these substances contain three carbon atoms.

(a) Explain why members of a homologous series have similar chemical properties.

.............................................................................................................................................. [1]

(b) Name the homologous series to which propanoic acid belongs.

.............................................................................................................................................. [1]

(c) State the general formula of the homologous series to which propanoic acid belongs.

.............................................................................................................................................. [1]

(g) Propanoic acid reacts with aqueous sodium carbonate to form a salt.

(i) Suggest the name of the salt formed.

....................................................................................................................................... [1]

(ii) Suggest the formula of the anion in this salt.

....................................................................................................................................... [1]

(h) Propanoic acid forms an ester when it reacts with ethanol in the presence of a catalyst.

(i) Suggest a suitable catalyst. (extended only)

....................................................................................................................................... [1]

(ii) Name the ester formed. (extended only)

....................................................................................................................................... [1]

(iii) Draw the displayed formula of this ester. (extended only)

[2]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

6 Some symbol equations and word equations, A to J, are shown.

A Fe3+ + 3OH– → Fe(OH)3

B H+ + OH– → H2O
C ethane + chlorine → chloroethane + hydrogen chloride
D C12H26 → C8H18 + C4H8
E ethene + steam → ethanol
F chlorine + aqueous potassium iodide → iodine + aqueous potassium chloride
G C6H12O6 → 2C2H5OH + 2CO2
H ethanoic acid + ethanol → ethyl ethanoate + water
I calcium carbonate → calcium oxide + carbon dioxide
J 6CO2 + 6H2O → C6H12O6 + 6O2

Use the equations to answer the questions that follow.

Each equation may be used once, more than once, or not at all.

Give the letter, A to J, for the equation that represents: (extended only)

(c) the formation of an ester ...................................................................................................... [1]

11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

7 Ethanol is manufactured by two methods:

method 1 fermentation of aqueous glucose

method 2 catalytic addition of steam to an alkene.

(e) Ethanol can be converted to ethanoic acid by reacting it with an acidified oxidising agent.

(i) Name the acidified oxidising agent. (extended only)

....................................................................................................................................... [1]

(ii) State, in terms of redox, what type of reagent ethanol is in this reaction. (extended only)

....................................................................................................................................... [1]

(f) Ethanoic acid reacts with calcium to form a salt and one other product.

(i) Name the salt.

....................................................................................................................................... [1]

(ii) Write the formula of the salt.

....................................................................................................................................... [1]

(iii) Identify the other product.

....................................................................................................................................... [1]
11.7 Carboxylic acids QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

8 Ethanoic acid is manufactured by the reaction of methanol with carbon monoxide.

An equilibrium mixture is produced.

CH3OH(g) + CO(g) CH3COOH(g)

(e) Ethanoic acid is a member of the homologous series of carboxylic acids.

State the general formula of this homologous series.

.............................................................................................................................................. [1]

(f) Draw the structure of the carboxylic acid containing three carbon atoms. Show all of the atoms
and all of the bonds.

[2]

(g) When carboxylic acids react with alcohols, esters are produced.

The formula of ester X is CH3CH2CH2COOCH3.

(i) Name ester X. (extended only)

....................................................................................................................................... [1]

(ii) Give the name of the carboxylic acid and the alcohol that react together to produce ester X.

(extended only)

carboxylic acid ....................................................................................................................

alcohol ................................................................................................................................
[2]
11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 3
Questions are applicable for both core and extended candidates

1 (f) Ethene reacts with steam to produce ethanol.

(i) Complete the symbol equation for this reaction.

C2H4 + ........... → ...................... [2]

(ii) Choose the word which describes the type of catalyst used in this reaction.

Draw a circle around your chosen answer.

acid alkali metal salt [1]

2 Fig. 7.1 shows the displayed formula of mesaconic acid.

H O

H C C
C O H
H
H O C
C H

Fig. 7.1

(e) Ethanol can be manufactured by fermentation.

Complete the word equation for one other method of manufacturing ethanol.

................................ + ................................ → ethanol [2]

3 (d) Ethanoic acid can be converted to ethanol.

Name the two products formed when ethanol undergoes complete combustion.

................................................................... and ................................................................... [2]

11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

4 (a) Fig. 6.1 shows the displayed formula of a molecule of crotyl alcohol.

H H H

H C C C C O H

H H H

Fig. 6.1

(i) On Fig. 6.1 draw a circle around the alcohol functional group. [1]

(ii) Describe the feature of crotyl alcohol that shows it is an unsaturated compound.

....................................................................................................................................... [1]

(iii) Deduce the molecular formula of crotyl alcohol.

....................................................................................................................................... [1]

(iv) Crotyl alcohol is soluble in water.

The boiling point of crotyl alcohol is 121 °C.

The boiling point of water is 100 °C.

Suggest how fractional distillation can be used to separate a mixture of crotyl alcohol and
water.

.............................................................................................................................................

.............................................................................................................................................

....................................................................................................................................... [2]

(b) Ethanol is also an alcohol.

Describe two conditions for the manufacture of ethanol by the fermentation of aqueous glucose.

1 .................................................................................................................................................

2 .................................................................................................................................................
[2]
11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

5 (a) The structures of four organic compounds, C, D, E and F, are shown.

C D

H H H H H H

H C C C H C C C O H

H H H H H

E F

H H H H Br Br

H C C C C H H C C H

H H H H H H

Answer the following questions about these compounds.

Each compound may be used once, more than once or not at all.

State which compound, C, D, E or F:

(i) decolourises aqueous bromine ..................................................................................... [1]

(ii) is an alcohol .................................................................................................................. [1]

(iii) is unsaturated ............................................................................................................... [1]

(iv) is in the same homologous series as ethane. .............................................................. [1]

11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

6 (a) The structure of lactic acid is shown.

H C H

H O C H

C
O O

(i) On the structure, draw a circle around the alcohol functional group. [1]

(ii) Deduce the formula of lactic acid to show the number of carbon, hydrogen and oxygen
atoms.

....................................................................................................................................... [1]

(b) Ethanol is an alcohol.

(i) Complete the sentence about ethanol using a word from the list.

ethane ethene methane poly(ethene)

Ethanol is manufactured by fermentation or from ................................... . [1]

(ii) State two conditions needed for fermentation.

1 ..........................................................................................................................................

2 ..........................................................................................................................................
[2]

(iii) Ethanol is used in drinks and as a fuel.

State one other use of ethanol.

....................................................................................................................................... [1]

(iv) Name one physical property that can be used to determine if a sample of ethanol is pure
or impure.

....................................................................................................................................... [1]

(c) Ethanol and methanol are in the same homologous series.

Explain the meaning of the term homologous series.

....................................................................................................................................................

....................................................................................................................................................
[2]

[Total: 9]
11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 4
Questions are applicable for both core and extended candidates
unless indicated in the question

7 Some symbol equations and word equations, A to J, are shown.

A Fe3+ + 3OH– → Fe(OH)3

B H+ + OH– → H2O
C ethane + chlorine → chloroethane + hydrogen chloride
D C12H26 → C8H18 + C4H8
E ethene + steam → ethanol
F chlorine + aqueous potassium iodide → iodine + aqueous potassium chloride
G C6H12O6 → 2C2H5OH + 2CO2
H ethanoic acid + ethanol → ethyl ethanoate + water
I calcium carbonate → calcium oxide + carbon dioxide
J 6CO2 + 6H2O → C6H12O6 + 6O2

Use the equations to answer the questions that follow.

Each equation may be used once, more than once, or not at all.

Give the letter, A to J, for the equation that represents:

(e) fermentation ......................................................................................................................... [1]

11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

8 Ethanol is manufactured by two methods:

method 1 fermentation of aqueous glucose

method 2 catalytic addition of steam to an alkene.

(a) Method 1 takes place at room temperature and pressure.

State two other conditions needed in method 1.

1 .................................................................................................................................................

2 .................................................................................................................................................
[2]

(b) (i) State the typical temperature and pressure used in method 2.

temperature .............................. °C

pressure .................................... kPa

[2]

(ii) Name the alkene used in method 2.

....................................................................................................................................... [1]

(iii) State why the reaction in method 2 is referred to as an addition reaction.

....................................................................................................................................... [1]

(c) The catalyst in method 2 is phosphoric acid, H3PO4. Dilute phosphoric acid is a weak acid
which contains phosphate ions, PO43–.

(i) State what is meant by the term acid.

....................................................................................................................................... [1]

(ii) State the meaning of weak in the term weak acid.

....................................................................................................................................... [1]

(iii) Determine the oxidation number of phosphorus in the PO43– ion.

Show your working.

oxidation number = .............................. [2]

11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

(d) Give one advantage of each method of production of ethanol. (extended only)

method 1 ....................................................................................................................................

method 2 ....................................................................................................................................
[2]

(e) Ethanol can be converted to ethanoic acid by reacting it with an acidified oxidising agent.

(i) Name the acidified oxidising agent.

....................................................................................................................................... [1]

(ii) State, in terms of redox, what type of reagent ethanol is in this reaction.

....................................................................................................................................... [1]
11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

9 Alkynes and alkenes are homologous series of unsaturated hydrocarbons.

All alkynes contain a C≡C triple bond.

(d) Ethene can be converted to ethanoic acid by a two-stage process.

In stage one, ethene is converted to ethanol by catalytic addition.

C2H4 + H2O → C2H5OH

(i) Suggest why stage one is called an addition reaction.

...................................................................................................................................... [1]

(ii) A catalyst is used in stage one.

State one other condition that must be used.

...................................................................................................................................... [1]

(iii) State what must be reacted with ethanol to form ethanoic acid.

...................................................................................................................................... [2]

10 he names of four esters are listed.

methyl propanoate
ethyl propanoate
propyl propanoate
butyl propanoate

(c) All four of the esters can be made by reacting different alcohols with the same substance.

(i) Name this substance and draw its structure. Show all of the atoms and all of the bonds.

name .......................................................

structure

(ii) Name the alcohol used to make methyl propanoate.

....................................................................................................................................... [1]
11.6 Alcohols QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

11 A list of substances is shown.

aluminium oxide carbon dioxide chlorine diamond ethanol

glucose iron(III) oxide limestone nitrogen oxygen

Answer the questions using the list of substances.

Each substance may be used once, more than once or not at all.

State which of the substances:

(c) are two products of fermentation

.................................................................... and .................................................................. [2]

11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 3
Questions are applicable for both core and extended candidates

1 Alkenes are a homologous series of hydrocarbons which are made by cracking larger alkane
molecules.

(a) (i) Write the general formula for alkenes.

....................................................................................................................................... [1]

(ii) Explain the need for cracking larger alkane molecules.

.............................................................................................................................................

....................................................................................................................................... [1]

(iii) Describe two conditions needed for cracking.

1 ..........................................................................................................................................

2 ..........................................................................................................................................
[2]

(b) Alkenes are unsaturated compounds.

State the meaning of the term unsaturated.

....................................................................................................................................................

.............................................................................................................................................. [1]

(c) Table 4.1 shows the boiling points of some alkenes.

Table 4.1

boiling point
alkene
/ °C
ethene –104
propene
butene –6
pentene 30
hexene 63

(i) Predict the boiling point of propene.

.................................................................................................................................. °C [1]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

(ii) The melting point of butene is –185 °C.

Deduce the physical state of butene at –100 °C.

Give a reason for your answer.

physical state ......................................................................................................................

reason .................................................................................................................................

.............................................................................................................................................
[2]

(f) Ethene reacts with steam to produce ethanol.

(i) Complete the symbol equation for this reaction. (extended only)

C2H4 + ........... → ...................... [2]

(ii) Choose the word which describes the type of catalyst used in this reaction.

Draw a circle around your chosen answer. (extended only)

acid alkali metal salt [1]

11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

2 (a) Fig. 7.1 shows the displayed formula of mesaconic acid.

H O

H C C
C O H
H
H O C
C H

Fig. 7.1

(i) On Fig. 7.1 draw a circle around one carboxylic acid functional group. [1]

(ii) Deduce the molecular formula of mesaconic acid.

....................................................................................................................................... [1]

(iii) Mesaconic acid is a colourless compound.

Describe the colour change when excess mesaconic acid is added to aqueous bromine.

from ............................................................ to ............................................................. [2]

11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

3 Fig. 7.1 shows the displayed formula of compound S.

H C O H

H C H

C
O O H

Fig. 7.1

(b) Compound S can be converted to acrylic acid.

The molecular formula of acrylic acid is C3H4O2.

(i) Complete Table 7.1 to calculate the relative molecular mass of acrylic acid.

Table 7.1

number relative
atom
of atoms atomic mass

carbon 3 12 3 × 12 = 36

hydrogen 1

oxygen 16

relative molecular mass = .............................. [2]

(ii) Acrylic acid is an unsaturated compound.

Describe a test for an unsaturated compound.

test ......................................................................................................................................

observations .......................................................................................................................
[2]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

4 Hydrogen is a fuel which can be obtained from water by electrolysis.

Refinery gas and petrol are fuels obtained by the fractional distillation of petroleum.

(e) More petrol can be made by cracking less useful petroleum fractions.

(i) Define the term cracking.

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

(ii) Complete the equation for the cracking of dodecane, C12H26, to form ethene and one
other hydrocarbon.

C12H26 → C2H4 + .......... [1]

11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

5 (a) The structures of four organic compounds, C, D, E and F, are shown.

C D

H H H H H H

H C C C H C C C O H

H H H H H

E F

H H H H Br Br

H C C C C H H C C H

H H H H H H

Answer the following questions about these compounds.

Each compound may be used once, more than once or not at all.

State which compound, C, D, E or F:

(i) decolourises aqueous bromine ..................................................................................... [1]

(ii) is an alcohol .................................................................................................................. [1]

(iii) is unsaturated ............................................................................................................... [1]

(iv) is in the same homologous series as ethane. .............................................................. [1]

(d) Some hydrocarbons are formed by the process of cracking.

(i) State the meaning of the term cracking.

.............................................................................................................................................

.............................................................................................................................................

....................................................................................................................................... [2]

(ii) Describe the conditions needed for cracking.

.............................................................................................................................................

....................................................................................................................................... [2]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

6 The structures of seven compounds, A, B, C, D, E, F and G, are shown.

A B C D
H H H H H O
S
C C C H C C C
O O
H H
H H H H H O H

E F G
H H H H H

H C C O H H C C C H O C O

H H H H H

Answer the following questions about these structures.

Each structure may be used once, more than once or not at all.

(a) State which structure, A, B, C, D, E, F or G, represents:

(i) a compound that contributes to acid rain

....................................................................................................................................... [1]

(ii) a product of respiration

....................................................................................................................................... [1]

(iii) a hydrocarbon that decolourises aqueous bromine

....................................................................................................................................... [1]

(iv) a carboxylic acid

....................................................................................................................................... [1]

(v) a compound that is the main constituent of natural gas.

....................................................................................................................................... [1]

(b) Compound C can be produced by cracking the kerosene fraction of petroleum.

(i) State the meaning of the term cracking.

.............................................................................................................................................

....................................................................................................................................... [2]

(ii) Complete the chemical equation for the cracking of C13H28 to form C8H18 and one other
hydrocarbon.

C13H28 → C8H18 + .............................. [1]

[Total: 8]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 4
Questions are applicable for both core and extended candidates
unless indicated in the question

7 Butane and but-1-ene are colourless gases at room temperature and pressure.

(a) Suggest why but-1-ene diffuses quicker than butane.

.............................................................................................................................................. [1]

(b) Identify the products formed when butane undergoes complete combustion.

.............................................................................................................................................. [1]

(d) When but-1-ene reacts with steam, two possible products form.

(i) Identify the type of catalyst which is used in this reaction. (extended only)

....................................................................................................................................... [1]

(ii) Name and draw the displayed formulae of the two possible products. (extended only)

product 1 product 2

name ............................................................... name ...............................................................

displayed formula displayed formula

[4]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

8 This question is about organic compounds.

(b) The structure of compound A is shown in Fig. 7.1.

COOH H

C C

H C H2 O H

Fig. 7.1

(i) Deduce the molecular formula of compound A.

....................................................................................................................................... [1]

(ii) There are three functional groups in compound A.

Name the homologous series of compounds that contain the following functional groups:

–C=C– ................................................................................................................................

–OH ....................................................................................................................................

–COOH. ..............................................................................................................................
[3]

(iii) State what is observed when compound A is added to:

aqueous bromine ................................................................................................................

aqueous sodium carbonate. ...............................................................................................

[2]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

9 This question is about alkanes and alkenes.

(a) Short-chain alkanes and alkenes can be formed from long-chain alkanes in a chemical reaction.

(i) Name the type of chemical reaction which forms short-chain alkanes and alkenes from
long-chain alkanes.

....................................................................................................................................... [1]

(ii) Decane has 10 carbon atoms. It forms ethane and ethene as the only products in this type
of chemical reaction.

Write the chemical equation for this reaction.

....................................................................................................................................... [3]

(b) Ethane reacts with chlorine at room temperature to form chloroethane, C2H5Cl, and one other
product.

(i) Name the other product formed.

....................................................................................................................................... [1]

(ii) State the condition needed for this reaction to take place.

....................................................................................................................................... [1]

(c) Ethene reacts with chlorine at room temperature to form dichloroethane, C2H4Cl 2.

C2H4 + Cl 2 → C2H4Cl 2

(i) State why this is an addition reaction. (extended only)

....................................................................................................................................... [1]
11.5 Alkenes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

10 Ethene is an alkene which reacts with bromine as shown in the equation.

C2H4 + Br2 → C2H4Br2

(a) Write the general formula of alkenes.

.............................................................................................................................................. [1]

(b) Describe the colour change seen when ethene is bubbled through aqueous bromine.

from ................................................................ to ................................................................ [1]

(c) In this reaction only one product is formed from two reactants.

Name this type of organic reaction. (extended only)

.............................................................................................................................................. [1]

11 Some symbol equations and word equations, A to J, are shown.

A Fe3+ + 3OH– → Fe(OH)3

B H+ + OH– → H2O
C ethane + chlorine → chloroethane + hydrogen chloride
D C12H26 → C8H18 + C4H8
E ethene + steam → ethanol
F chlorine + aqueous potassium iodide → iodine + aqueous potassium chloride
G C6H12O6 → 2C2H5OH + 2CO2
H ethanoic acid + ethanol → ethyl ethanoate + water
I calcium carbonate → calcium oxide + carbon dioxide
J 6CO2 + 6H2O → C6H12O6 + 6O2

Use the equations to answer the questions that follow.

Each equation may be used once, more than once, or not at all.

Give the letter, A to J, for the equation that represents:

(f) cracking. .............................................................................................................................. [1]

11.4 Alkanes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 3
Questions are applicable for both core and extended candidates

1 (d) Ethene can be converted to ethane.

(i) Ethane is an alkane.

Name the type of bonding in alkanes.

....................................................................................................................................... [1]

(ii) Draw the displayed formula of a molecule of ethane.

[1]

(iii) Complete this sentence.

Alkanes are unreactive except in terms of combustion and substitution by

............................ . [1]

(iv) Complete the symbol equation for the complete combustion of methane.

CH4 + .....O2 → ............ + 2H2O [2]

11.4 Alkanes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

2 A list of substances is shown.

ammonium nitrate
carbon monoxide
copper(II) chloride
ethane
ethene
litmus
methane
methyl orange
sodium chloride
sodium sulfate
sulfur dioxide
thymolphthalein

Answer the following questions using only the substances from the list.
Each substance may be used once, more than once or not at all.

Give the name of the substance that:

(e) is a hydrocarbon with a total of five atoms in a molecule

.............................................................................................................................................. [1]

3 Hydrogen is a fuel which can be obtained from water by electrolysis.

Refinery gas and petrol are fuels obtained by the fractional distillation of petroleum.

(d) Petrol is a mixture of alkanes.

One of the alkanes in petrol is octane, C8H18.

Name the two products formed when octane is burnt in excess air.

................................................................... and ................................................................... [2]

4 This question is about fuels and energy production.

(d) Name the two products formed when a hydrocarbon fuel undergoes complete combustion.

................................................................... and ................................................................... [2]

11.4 Alkanes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

Paper 4
Questions are applicable for both core and extended candidates
unless indicated in the question

5 Butane and but-1-ene are colourless gases at room temperature and pressure.

(b) Identify the products formed when butane undergoes complete combustion.

.............................................................................................................................................. [1]

(c) One molecule of butane reacts with one molecule of chlorine in the presence of ultraviolet light.
During the reaction, one hydrogen atom in butane is replaced by one chlorine atom.

(i) Name the type of reaction which needs ultraviolet light. (extended only)

....................................................................................................................................... [1]

(ii) State the purpose of ultraviolet light during this reaction. (extended only)

....................................................................................................................................... [1]

(iii) Name the type of reaction which takes place when one atom of chlorine replaces one
atom of hydrogen. (extended only)

....................................................................................................................................... [1]

(iv) Determine how many different structural isomers can form during this reaction.
(extended only)

....................................................................................................................................... [1]
11.4 Alkanes QP - CAIE Chemistry IGCSE PhysicsAndMathsTutor.com

6 Propane, propene, propan 1 ol and propanoic acid are members of different homologous series.
Molecules of these substances contain three carbon atoms.

(e) Propane and propene can be manufactured by heating decane, C10H22, in the presence of a
catalyst. One other product is formed.

(i) Complete the equation for this reaction.

C10H22 → ........................... + ........................... + ........................... [2]

(ii) Name this manufacturing process.

....................................................................................................................................... [1]

7 This question is about organic compounds.

(a) Butane reacts with chlorine in a photochemical reaction.

C4H10 + Cl 2 → C4H9Cl + HCl

(i) State the meaning of the term photochemical. (extended only)

....................................................................................................................................... [1]

(ii) An organic compound with the formula C4H9Cl is formed when one molecule of butane
reacts with one molecule of chlorine.

Draw the displayed formulae of two possible structural isomers with the formula C4H9Cl
formed in this reaction. (extended only)

[2]