Shapes of organic molecules; σ and π bonds — Paper 1 · A Level Chemistry 9701

5 Which diagram describes the formation of a π bond from the overlap of its orbitals? A B C D

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2006

6 Lycra is a polyurethane fibre used in the fashion industry. It is a polymer made from two monomers, one of which has the following formula. O=C=N–(CH2)n –N=C=O What is the O–C–N bond angle in this molecule? A 90 ° B 109 ° C 120 ° D 180 °

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2007

22 Chloroethene, CH2=CHCl, is the monomer of PVC. What are the C−C−C bond angles along the polymeric chain in PVC? A They are all 109.5°. B Half are 109.5° and half are 120°. C They are all 120°. D They are all 180°.

1 marks

Answer: A

This question in 9701/11 May/June 2008

6 In which reaction does the carbon-containing product have a smaller bond angle than the organic reactant? A bromoethane refluxed with ethanolic sodium hydroxide B complete combustion of methane in air C methane and an excess of chlorine under ultraviolet light D polymerisation of ethene

1 marks

Answer: D

This question in 9701/11 May/June 2009

23 Polymerisation of chloroethene gives PVC. How does the carbon-carbon bond in PVC compare with that in chloroethene? A longer and stronger B longer and weaker C shorter and stronger D shorter and weaker

1 marks

Answer: B

This question in 9701/11 May/June 2009

7 Organic nitrates in photochemical smog can cause breathing difficulties. The diagram shows an example of an organic nitrate molecule. H 1 3 H C C O O NO2 2 H O What is the correct order of the bond angles shown in ascending order (smallest first)? A 1 → 2 → 3 B 2 → 1 → 3 C 3 → 1 → 2 D 3 → 2 → 1

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2010

37 The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Which statements about cholesterol are correct? 1 The molecule contains a secondary alcohol group. 2 The molecule contains two π bonds. 3 All carbon atoms in the four rings lie in the same plane.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2010

33 Which statements about covalent bonds are correct? 1 A triple bond consists of one π bond and two σ bonds. 2 The electron density in a σ bond is highest along the axis between the two bonded atoms. 3 A π bond restricts rotation about the σ bond axis.

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2010

6 Organic nitrates in photochemical smog can cause breathing difficulties. The diagram shows an example of an organic nitrate molecule. H 1 3 H C C O O NO2 2 H O What is the correct order of the bond angles shown in ascending order (smallest first)? A 1 → 2 → 3 B 2 → 1 → 3 C 3 → 1 → 2 D 3 → 2 → 1

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2010

36 The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Which statements about cholesterol are correct? 1 The molecule contains a secondary alcohol group. 2 The molecule contains two π bonds. 3 All carbon atoms in the four rings lie in the same plane.

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2010

26 How many isomers with the formula C5H10 have structures that involve π bonding? A 3 B 4 C 5 D 6

1 marks

Answer: D

This question in 9701/12 May/June 2011

5 Two conversions are outlined below. NH4 + → NH3 C2H4 → C2H6 What similar feature do these two conversions have? A a lone pair of electrons in the product B change in oxidation state of an element C decrease in bond angle of the species involved D disappearance of a π bond

1 marks

Answer: C

This question in 9701/11 May/June 2012

37 What is always involved in a carbon-carbon π bond? 1 a shared pair of electrons 2 a sideways overlap of p orbitals 3 delocalised electrons

1 marks

Answer: B

This question in 9701/11 May/June 2012

6 Two conversions are outlined below. NH4 + → NH3 C2H4 → C2H6 What similar feature do these two conversions have? A a lone pair of electrons in the product B change in oxidation state of an element C decrease in bond angle of the species involved D disappearance of a π bond

1 marks

Answer: C

This question in 9701/13 May/June 2012

38 What is always involved in a carbon-carbon π bond? 1 a shared pair of electrons 2 a sideways overlap of p orbitals 3 delocalised electrons

1 marks

Answer: B

This question in 9701/13 May/June 2012

20 Carvone is found in spearmint. CH3 O C H C C H2C CH2 C C H H3C CH2 carvone How many σ and π bonds are present in this molecule? σ π A 13 3 B 22 3 C 22 6 D 25 3

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2012

20 Carvone is found in spearmint. CH3 O C H C C H2C CH2 C C H H3C CH2 carvone How many σ and π bonds are present in this molecule? σ π A 13 3 B 22 3 C 22 6 D 25 3

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2012

6 Which diagram represents the overlap of two orbitals which will form a π bond? A B C D

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2012

21 The diagram shows a molecule that has σ bonds and π bonds. O C CH2 CH CH2 O CH2 CH CH2 How many σ bonds are present in this molecule? A 15 B 17 C 18 D 21

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2012

33 Which substances contain delocalised electrons? 1 cyclohexene 2 graphite 3 sodium

1 marks

Answer: C

This question in 9701/12 May/June 2013

30 Which types of bond breakage and bond formation occur in the addition polymerisation of alkenes? bond breakage bond formation A π only σ only B π only σ and π C σ and π σ only D σ and π σ and π

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2013

30 Which types of bond breakage and bond formation occur in the addition polymerisation of alkenes? bond breakage bond formation A π only σ only B π only σ and π C σ and π σ only D σ and π σ and π

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2013

33 Which elements have atoms which can form π bonds with atoms of other elements? 1 oxygen 2 nitrogen 3 fluorine

1 marks

Answer: B

This question in 9701/12 May/June 2014

10 The double bond between the two carbon atoms in an ethene molecule consists of one σ bond and one π bond. Which orbitals overlap to form each of these bonds? σ bond π bond A sp2–sp2 p–p B sp2–sp2 sp2–sp2 C sp3–sp3 p–p D sp3–sp3 sp2–sp2

1 marks

Answer: A

This question in 9701/11 May/June 2015

37 In which structures do the four carbon atoms labelled C lie in the same plane? 1 2 3 C C C C C C C C C C C C

1 marks

Answer: B

This question in 9701/12 May/June 2015

20 People who take statin drugs to control their blood cholesterol may also take ‘coenzyme Q10’. The diagram shows a simplified structure of one form of this coenzyme. O CH3O CH3O H O n coenzyme Q10 Which row describes this structure correctly? number of π bonds the coenzyme is in one molecule A an aldehyde n + 2 B an aldehyde n + 4 C a ketone n + 2 D a ketone n + 4

1 marks

Answer: D

This question in 9701/12 Feb/March 2016

7 Methyl isocyanate, CH3NCO, is a toxic liquid which is used in the manufacture of some pesticides. What is the approximate angle between the bonds formed by the N atom in a molecule of methyl isocyanate? A B C D N C O N C O N C O H3C N C O H3C H3C H3C 104° 109° 120° 180°

1 marks

Answer: C

This question in 9701/13 May/June 2016

32 Which elements can form π bonds in their compounds? 1 carbon 2 oxygen 3 nitrogen

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2016

32 Which elements can form π bonds in their compounds? 1 carbon 2 oxygen 3 nitrogen

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2016

6 Which reaction involves a decrease in the bond angle at a carbon atom? A bromoethane refluxed with ethanolic sodium hydroxide B complete combustion of methane in air C ethanol heated with conc. H2SO4 D polymerisation of ethene

1 marks

Answer: D

This question in 9701/12 May/June 2017

38 The diagram shows the monomer used to make polyvinyl chloride, PVC. H H C C H Cl Assuming that one particular molecule of the polymer forms from n molecules of the monomer (where n is many thousands), which statements are correct? 1 The relative molecular mass of this polymer molecule is approximately 62.5n. 2 There are n chiral carbon atoms in this polymer molecule. 3 There are 5n σ bonds in one polymer molecule.

1 marks

Answer: B

This question in 9701/12 May/June 2017

37 In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexane

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2017

4 Ethane burns in oxygen to produce carbon dioxide and water vapour. Which bond angles are present in the molecules of ethane and its combustion products? ethane combustion products A 90° 104.5° and 180° B 90° 109.5° and 120° C 109.5° 104.5° and 180° D 109.5° 109.5° and 180°

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2017

23 Which types of bond are broken and formed in the addition polymerisation of alkenes? type of type of bond broken bond formed A π only σ only B π only σ and π C σ and π σ only D σ and π σ and π

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2017

37 In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexane

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2017

4 Which molecule contains a nitrogen atom with sp hybridised orbitals? A CH3CH2NH2 B HNO3 C HCN D NH3

1 marks

Answer: C

This question in 9701/12 Feb/March 2018

1 Which feature is present in both ethene and poly(ethene)? A bond angles of 109° B π covalent bonds C σ covalent bonds D sp3 orbitals

1 marks

Answer: C

This question in 9701/12 May/June 2018

4 Which statement describes the bond between carbon and hydrogen in an ethene molecule? A a π bond between an s orbital and an sp2 orbital B a π bond between an s orbital and an sp3 orbital C a σ bond between an s orbital and an sp2 orbital D a σ bond between an s orbital and an sp3 orbital

1 marks

Answer: C

This question in 9701/13 May/June 2018

37 2-methylpropene can react in more than one way with chlorine. One of the reactions follows the pathway shown. CH3 CH3 CH3 + CH2 C + Cl 2 → Cl CH2 C + Cl – → Cl CH2 C + HCl CH3 CH3 CH2 2-methylpropene intermediate product Which statements about this mechanism are correct? 1 The intermediate has all carbon atoms in the same plane. 2 There is an electrophilic attack on the double bond. 3 It is a free radical mechanism.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2018

21 The diagram shows a molecule that has σ bonds and π bonds. O CH2 CH CH2 C O CH2 CH CH2 How many σ bonds are present in this molecule? A 15 B 17 C 18 D 21

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2018

5 Histidine is an amino acid. histidine H 2 H H 1 H N O C H N C C C C 3 C N H H O H H What are the approximate bond angles 1, 2, and 3? 1 2 3 A 109.5 107 90 B 120 107 109.5 C 120 120 90 D 120 120 109.5

1 marks

Answer: B

This question in 9701/12 Feb/March 2019

37 The diagram shows the structure of cholesterol. cholesterol CH3 CH3 CH3 HO Which statements about cholesterol are correct? 1 The molecule contains a secondary alcohol group. 2 The molecule contains two π bonds. 3 All carbon atoms in the four rings lie in the same plane.

1 marks

Answer: D

This question in 9701/12 Feb/March 2019

20 The diagrams show two different compounds. O O 1 2 What is ● the total number of structural isomers, including compound 2, that could be formed by adding a second methyl group to the ring of compound 1, ● the number of π electrons in each compound? number of number of isomers π electrons A 3 2 B 3 4 C 5 2 D 5 4

1 marks

Answer: D

This question in 9701/11 May/June 2019

4 A σ bond is made between two carbon atoms in a molecule of ethene. Which diagram shows the orbital overlap that occurs to form this bond? A B C D

1 marks

Answer: C

This question in 9701/12 May/June 2019

38 Bromine reacts with ethene in an addition reaction. Which statements about this reaction are correct? 1 It is the basis of a test for unsaturation in alkenes. 2 It leads to an increase in each of the H–C–H bond angles. 3 A nucleophile attacks the C=C bond in ethene.

1 marks

Answer: D

This question in 9701/13 May/June 2019

4 Four compounds are shown. C2H4 C2H5OH CH3CHO CH3CO2H How many of these compounds have an odd number of σ bonds? A 1 B 2 C 3 D 4

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2019

37 The structure of tiglic acid is CH3CH=C(CH3)CO2H. Which statements about the properties of one molecule of this acid are correct? 1 It contains two π bonds. 2 It contains four lone pairs of electrons. 3 It has all its atoms in the same plane.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2019

4 Four compounds are shown. C2H4 C2H5OH CH3CHO CH3CO2H How many of these compounds have an odd number of σ bonds? A 1 B 2 C 3 D 4

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2019

37 The structure of tiglic acid is CH3CH=C(CH3)CO2H. Which statements about the properties of one molecule of this acid are correct? 1 It contains two π bonds. 2 It contains four lone pairs of electrons. 3 It has all its atoms in the same plane.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2019

30 The diagram shows the structure of compound Q. Q O O X HO Y O O Two of the rings, X and Y, contain a C=C bond. Which row is correct? number of ester groups description of in one molecule of Q rings X and Y A 1 both are planar B 1 neither is planar C 2 both are planar D 2 neither is planar

1 marks

Answer: D

This question in 9701/12 Feb/March 2020

3 When considering one molecule of ethene, which row describes both the hybridisation of the atomic orbitals in the carbon atoms and the overall bonding? hybridisation bonding A sp2 4 σ bonds 1 π bond B sp2 5 σ bonds 1 π bond C sp3 4 σ bonds 1 π bond D sp3 5 σ bonds 1 π bond

1 marks

Answer: B

This question in 9701/11 May/June 2020

4 The structure of compound A is shown. compound A CH3 CH3 CH CH C CH C CH CH2OH CH3 CH3 Some of the carbon atoms in compound A have a tetrahedral arrangement of bonds. Some of the carbon atoms in compound A have a trigonal planar arrangement of bonds. How many carbon atoms are there of each type? tetrahedral trigonal planar A 5 12 B 8 8 C 9 6 D 9 8

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2020

34 Which molecules contain at least one bond angle of 120? 1 C2H4 2 PF5 3 NCl 3

1 marks

Answer: B

This question in 9701/11 May/June 2021

38 Which changes are commonly involved in the formation of an addition polymer? 1 the formation of a -bond 2 the breaking of a -bond 3 the change in hybridisation of the orbitals of a carbon atom from sp2 to sp3

1 marks

Answer: A

This question in 9701/12 May/June 2021

18 Which row is correct? shape bonds present ammonia ammonium ammonia ammonium molecule ion molecule ion A pyramidal regular tetrahedral   B pyramidal regular tetrahedral   C regular tetrahedral pyramidal   D regular tetrahedral pyramidal  

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2021

5 Ethane and ethene are both hydrocarbon molecules. What is a feature of both molecules? A a planar structure B bond angles of 109 C  covalent bonds D  covalent bonds

1 marks

Answer: C

This question in 9701/12 May/June 2022

5 How many σ bonds are present in one H–C≡C–C(CH3)=CH(CH3) molecule? A 5 B 11 C 13 D 16

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2022

5 How many  bonds are present in one H–C≡C–C(CH3)=CH(CH3) molecule? A 5 B 11 C 13 D 16

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2022

27 How many and bonds are in the molecule HCCCH2CH2CHC(CH3)2? A 17 3 B 17 5 C 18 4 D 19 3

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2023

6 Which feature is present in both ethene and poly(ethene)? A bond angles of 109.5° B covalent bonds C covalent bonds D sp3 orbitals

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2023

27 How many and bonds are in the molecule HCCCH2CH2CHC(CH3)2? A 17 3 B 17 5 C 18 4 D 19 3

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2023

5 Which row shows the correct number of covalent bonds in a molecule of methylpropene? total number of sigma () total number of pi () bonds in the molecule bonds in the molecule A 10 1 B 10 2 C 11 1 D 11 2

1 marks

Answer: C

This question in 9701/12 Feb/March 2024

26 The diagram shows the structure of X. X NC H H H Which row is correct? number of type of hybridisation of  bonds in X the carbon atoms in X A 4 sp and sp2 B 4 sp2 and sp3 C 6 sp and sp2 D 6 sp2 and sp3

1 marks

Answer: C

This question in 9701/11 May/June 2024

33 The diagram shows a simplified structure of coenzyme Q10. coenzyme Q10 O CH3O CH3O H O n Which row describes the structure of coenzyme Q10 correctly? number of  bonds the coenzyme is in one molecule A an aldehyde n + 2 B an aldehyde n + 4 C a ketone n + 2 D a ketone n + 4

1 marks

Answer: D

This question in 9701/12 May/June 2024

6 A structure for borazole, N3B3H6, is shown. borazole H H B – N+ H N+ B – H B – N+ H H Which shape is borazole and how many  electrons are there in the structure? number of shape  electrons A non-planar 3 B non-planar 6 C planar 3 D planar 6

1 marks

Answer: D

This question in 9701/13 May/June 2024

25 The diagram shows the structural formula of a hydrocarbon molecule Q. molecule Q H H H C H C H H C H H H C C C C C C C H H H How many of the carbon atoms in molecule Q are sp2 hybridised? A 3 B 4 C 7 D 10

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2024

16 Propene, hydrogen cyanide and carbon dioxide each contain  bonds. Which molecules contain two  bonds? A carbon dioxide and hydrogen cyanide B carbon dioxide and propene C hydrogen cyanide and propene D hydrogen cyanide only

1 marks

Answer: A

This question in 9701/12 Feb/March 2025

39 What is the total number of sp3 hybridised atomic orbitals used in the bonding of but-2-ene? A 2 B 4 C 6 D 8

1 marks

Answer: D

This question in 9701/12 Feb/March 2025

39 The structural formula of hept-1,4,5-triene is shown. CH2CHCH2CHCCHCH3 How many of the carbon atoms in one molecule of hept-1,4,5-triene are sp2 hybridised? A 4 B 5 C 6 D 7

1 marks

Answer: A

This question in 9701/11 May/June 2025

8 The structure of a molecule found in food is shown. CH2OH OH OH OH OH O Four statements about the molecule are listed. 1 This molecule contains only  bonds. 2 This molecule contains both  and  bonds. 3 The six-membered ring is planar. 4 The six-membered ring is non-planar. Which two statements are correct? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: B

This question in 9701/13 May/June 2025

5 The bonding between two atoms of nitrogen in an N2 molecule involves the hybridisation of atomic orbitals to form sp orbitals. Which row is correct? type of orbital which contains formation of the  bond the lone pair of electrons on between the nitrogen atoms in N2 each nitrogen atom in N2 A an sp orbital from one atom overlaps p with an sp orbital of the other atom B an sp orbital from one atom overlaps sp with an sp orbital of the other atom C an s orbital from one atom overlaps p with a p orbital of the other atom D an s orbital from one atom overlaps sp with a p orbital of the other atom

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2025

25 Two statements about a molecule of methanal are given. 1 It is planar. 2 It contains three  bonds. Which statements are correct? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2025

6 NH3 and HCN react together to form NH4CN, an ionic compound. Which row states the number of coordinate bonds and the number of  bonds in one formula unit of NH4CN? number of coordinate bonds number of  bonds A 0 2 B 1 2 C 0 3 D 1 3

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2025