AQA AS Chemistry

Topic Questions

1.5 Molecules: Shapes & Forces

11 mark

What is the correct bond angle in a trigonal planar molecule?

  • 107°

  • 120°

  • 180°

  • 109.5°

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21 mark

Which statement is correct for a molecule of CCl4

 

Total number of valence electrons

Number of bonding pairs 

Number of lone pairs

A

30

4

2

B

32

4

0

C

34

4

1

D

16

4

0

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31 mark

Hydrazine, N2H4, is a precursor for multiple pharmaceutical compounds.

What is the bond angle for a molecule of hydrazine?

1

  • 107°

  • 120°

  • 180°

  • 109.5°

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41 mark

What is the correct shape of a borohydride, BH4-, molecule?

  • trigonal bipyramidal

  • square planar

  • tetrahedral

  • square planar

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51 mark

Which of the following compounds does not contain a polar bond?

  • CH3CH2Cl

  • CH2CH2

  • CH3CH2OH

  • CH3COOH

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61 mark

Which of the following has the highest boiling point?

  • CH3CH2CH3

  • CH3CH2CH2CH3

  • CH3CH2CH2CH2CH3

  • CH3CH2CH2CH2CH2CH3

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71 mark

Which of the following statements is not correct?

  • The strongest type of intermolecular force in ammonia is hydrogen bonding

  • The strongest type of intermolecular force in water is hydrogen bonding

  • The strongest type of intermolecular force in hydrogen chloride is permanent dipole-dipole

  • The strongest type of intermolecular forces in ethanol is permanent dipole-dipole

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81 mark

How many lone pairs are there in a molecule of PCl3?

  • 0

  • 1

  • 2

  • 3

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91 mark

Which of the following is correct?

 

Shape of SF6 molecule

Bond angle in SF6 molecule

A

Octahedral

90°

B

Square planar

90°

C

Trigonal bipyramidal 

120°

D

Tetrahedral 

109.5°

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101 mark

Which of the following compounds is polar?

  • CCl4

  • BF3

  • PH3

  • CH3CH3

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11 mark

What is the strongest intermolecular force in BF5 and CH3Br? 

 

BF5

CH3Br

A

Van der Waals’ 

Van der Waals’ 

B

Permanent dipole-dipole

Permanent dipole-dipole

C

Permanent dipole-dipole 

Van der Waals’

D

Van der Waals’

Permanent dipole-dipole

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21 mark

The correct shape and bond angle for the TlBr32- ion?

 

Shape

Bond angle

A

Pyramidal 

120°

B

Pyramidal

107°

C

Tetrahedral

109.5°

D

Tetrahedral

120°

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31 mark

Which of the following molecules will have the highest boiling point?

  • Propanal

  • Propanone

  • Propylamine

  • 2-fluoropropane

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41 mark

Which molecule can butanal can form hydrogen bonds with?

  • CH3CH2COOCH2CH3

  • CH3CH2CH2OH

  • CH3CH2COCH3

  • CH3CH2CHO

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51 mark

What is the correct shape of a ClF2- ion?

  • Linear

  • T-Shaped

  • Bent

  • Trigonal planar

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61 mark

Which molecule does not have five pairs of electrons around the central atom?

  • SF4

  • PF5

  • Cl F3

  • IF5

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71 mark

Which row in the table is not correct?

 

Molecule

Nonpolar

Polar

A

SO2

B

H2S

C

SF6

D

SF2

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81 mark

Which statement about hydrogen bonding is correct?

  • The surface tension in water is increased by the action of hydrogen bonds between the molecules

  • Hydrogen bonds are relatively shorter than the O-H bonds within the molecule

  • The molecules in ice are more densely packed together when water freezes

  • Hydrogen bonds are weaker than permanent dipole dipole forces

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91 mark

What is the correct order of boiling points for the following molecules, from lowest to highest?

 

Lowest -------------------------------------> Highest

A

CH3F

F2

CH3CH2F

HF

B

F2

CH3F

CH3CH2F

HF

C

F2

CH3CH2F

CH3F

HF

D

HF

CH3CH2F

CH3F

F2

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101 mark

Which compound has the highest boiling point?

  • CH3CH2OH

  • CH3CH2NH2

  • CH3CHO

  • CH3CH2Cl

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11 mark

Three lone pairs of electrons can be found around the central atom of which of the following ions?

  • PF6

  • SF5

  • BF2

  • ClF2

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21 mark

Which of the following changes of state shows only dispersion van der Waals’ forces being overcome?

  • CH3NH2 (l) → CH3NH2 (g)

  • H2O (s) → H2O (l)

  • CO2 (s) → CO2 (g)

  • C2H5OH (l) → C2H5OH (g)

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31 mark

The correct order of increasing boiling points for the following compounds is

  • 1-chlorobutane, butane, butan-1-ol

  • butan-1-ol, 1-chlorobutane, butane

  • butane, 1-chlorobutane, butan-1-ol

  • butan-1-ol, butane, 1-chlorobutane

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41 mark

How many lone pairs of electrons are there in a chlorine trifluoride, ClF3, molecule?

  • 1

  • 2

  • 3

  • 0

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51 mark

What is the correct shape and bond angle of the phosphonium ion, PH4+?

  • Tetrahedral and 109.5°

  • Square planar and 90°

  • V-shaped and 105°

  • Tetrahedral and 107°

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61 mark

Which molecule is nonpolar?

  • CH3CHICH3

  • BF3

  • BrF5

  • CH3CHO

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71 mark

What is the strongest type of intermolecular force exhibited in the amino acid molecule serine?

26

  • van der Waals

  • permanent dipole-dipole forces

  • hydrogen bonding

  • covalent bonding

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81 mark

Hexane, C6H14 and 2,2-dimethylbutane, CH3C(CH3)2CH2CH3, are two isomers of one another and have the same Mr of 86.0.

Hexane has a higher boiling point than 2,2-dimethylbutane.

Which of the following statements is not correct? 

  • hexane has a higher boiling point because it is a straight chain molecule

  • 2,2-dimethylbutane has a lower boiling point as it is a branched molecule

  • 2,2-dimethylbutane only contains van der Waals forces

  • hexane contains permanent dipole dipole forces

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91 mark

Which row in the table is correct? 

 

Molecule

Nonpolar

Polar

A

Methanol

B

1-bromopropane

C

Oxygen

D

Hydrogen cyanide

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101 mark

Which one of these species has a bond angle of 120°?

  • H3O+

  • TlBr32-

  • BCl3

  • NH3

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