A LevelChemistryOCRExam Questions2. Foundations in ChemistryThe Shapes of Simple Molecules & Ions

The Shapes of Simple Molecules & Ions (OCR A Level Chemistry A): Exam Questions

Exam code: H432

3 hours44 questions

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The Shapes of Simple Molecules & Ions

Easy
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Hard
1
1 mark

Which molecule is not planar?

  • C2H4

  • C2H6

  • H2CO

  • HCN

Choose your answer

2
1 mark

Which element has induced dipole–dipole interactions (London forces) in its solid lattice?

  • Boron

  • Magnesium 

  • Silicon 

  • Sulfur

Choose your answer

3
1 mark

What is the shape around the carbon atoms in graphene?

  • Linear

  • Pyramidal 

  • Tetrahedral 

  • Trigonal planar

Choose your answer

4
1 mark

A ‘dot-and-cross’ diagram for nitrogen trichloride, NCl3, is shown below.

Dot-and-cross diagram for nitrogen trichloride.

Which row shows the correct shape and bond angle in a molecule of NCl3?

 

Name of shape

Bond angle 

A

Pyramidal

104.5 °

B

Pyramidal

107 °

C

Tetrahedral

107 °

D

Trigonal planar

120 °

How did you do?

5
1 mark

Which molecule is non-polar?

  • SF6

  • H2O

  • PF3

  • NH3

Choose your answer

6
1 mark

Which substance contains hydrogen bonding in the liquid state?

  • CH3(CH2)4CH3

  • CH3(CH2)3CHFCH3

  • CH3(CH2)3COCH3

  • CH3(CH2)3CH(OH)CH3

Choose your answer

7
1 mark

The boiling point of hydrogen bromide is –67 °C.

The boiling point of hydrogen iodide is –34 °C.

The different boiling points can be explained in terms of the strength of bonds or interactions.

Which bonds or interactions are responsible for the higher boiling point of hydrogen iodide?

  • Covalent bonds

  • Hydrogen bonds

  • Induced dipole–dipole interactions

  • Permanent dipole–dipole interactions

Choose your answer

8
1 mark

What is the bond angle in a trigonal planar molecule?

  • 107°

  • 120°

  • 180°

  • 109.5°

Choose your answer

9
1 mark

Which row is correct for an SF6 molecule?

Shape

Bond angle

A

Octahedral

90°

B

Square planar

90°

C

Trigonal bipyramidal

120°

D

Tetrahedral

109.5°

    Choose your answer

    10
    1 mark

    Which row 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

      Choose your answer

      11
      1 mark

      What is the shape and bond angle of a molecule of hydrogen sulfide, H2S?

      • Linear, 180o

      • Non-linear, 104.5o

      • Tetrahedral, 109.5o

      • Trigonal planar, 120o

      Choose your answer

      1
      1 mark

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

      • Tetrahedral and 109.5°

      • Square planar and 90°

      • V-shaped and 105°

      • Tetrahedral and 107°

      Choose your answer

      2
      1 mark

      Which molecule is nonpolar?

      • CH3CHICH3  

      • BF3

      • BrF5

      • CH3CHO

      Choose your answer

      3
      1 mark

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

      • H3O+  

      • TlBr32-

      • BCl3

      • NH3

      Choose your answer

      4
      1 mark

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

      Chemical structure of serine, an amino acid, showing its molecular formula with hydroxyl, amine, and carboxyl groups.

      • London dispersion forces 

      • Permanent dipole-dipole forces

      • Hydrogen bonding

      • Covalent bonding

      Choose your answer

      5
      1 mark

      Which organic compound has the highest boiling point?

      • Butan-1-ol

      • Butane

      • 1-chlorobutane

      • Propane

      Choose your answer

      6
      1 mark

      Which molecule has the lowest boiling point?

      • CH3CH2CHO

      • CH3CH2CH2Cl

      • CH3CH2CH3

      • CH3CH2COOH

      Choose your answer

      7
      1 mark

      Why is water more dense than ice?

      • Ice contains hydrogen bonds, but water does not contain hydrogen bonds

      • Hydrogen bonds are stronger in water than in ice

      • Hydrogen bonds hold H2O molecules closer together in water 

      • Ice is a solid and water is a liquid 

      Choose your answer

      8
      1 mark

      Why does hexane have a higher boiling point than 2,2-dimethylbutane?

      • Hexane has a higher Mr than 2,2-dimethylbutane

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

      • 2,2-dimethylbutane only contains London dispersion forces 

      • Hexane contains permanent dipole dipole forces

      Choose your answer

      9
      1 mark

      Which element has induced dipole dipole interactions (London dispersion forces) in its solid lattice?

      • Sodium 

      • Diamond

      • Phosphorus 

      • Beryllium 

      Choose your answer

      10
      1 mark

      Four atoms, A-D, are labelled in the structure os alanine below.

      Chemical structure of alanine with the CH3 group labelled A, a CH group labelled B, a carboxylic carbon labelled C, and the NH2 group labelled D.

      Which atom has a trigonal planar arrangement of bonds around it?

        Choose your answer

        11
        1 mark

        Which compound has polar molecules?

        • OCl2

        • BCl3

        • BCl4

        • SCl6

        Choose your answer

        12
        1 mark

        The boiling point of butan-1-ol is 118 °C. The boiling point of 2-methylpropan-2-ol is 82 °C.

        Why is the boiling point of butan-1-ol higher than that of 2-methylpropan-2-ol?

        • Butan-1-ol has stronger induced dipole–dipole interactions because it has more electrons

        • Butan-1-ol has stronger induced dipole–dipole interactions because it has a straight-chain structure

        • Butan-1-ol can form hydrogen bonds while 2-methylpropan-2-ol cannot

        • Butan-1-ol is more stable because it is a primary alcohol

        Choose your answer

        13
        1 mark

        Which statement correctly explains the trend in the boiling points of the halogens from chlorine to iodine?

        • The boiling point increases because the permanent dipole-dipole interactions become stronger as the molecules become more polar.

        • The boiling point increases because the number of electrons increases, leading to stronger London (induced dipole-dipole) forces.

        • The boiling point decreases because the covalent bond strength decreases as the atomic radius increases.

        • The boiling point decreases because the shielding effect increases, weakening the attraction between molecules.

        Choose your answer

        1
        1 mark

        Which compound has non-polar molecules?

        • E-1,2-dichlorobut-2-ene

        • E-2,3-dichlorobut-2-ene

        • Z-2,3-dichlorobut-2-ene

        • Z-1,4-dichlorobut-2-ene

        Choose your answer

        2
        1 mark

        Four atoms, A-D, are labelled in the structure below

        Chemical structure of benzene-1,2-dicarboxylic acid, with four atoms labelled A, B, C and D

        Which atom has a v-shaped arrangement of bonds around it?

          Choose your answer

          3
          1 mark

          Which row has the correct shape, bond angle and explanation for the following molecules?

          Molecule

          Shape

          Bond angle

          Explanation

          A

          Ethanoic acid

          Pyramidal around the carbonyl carbon

          107o

          The carbon atom is sp2 hybridised so the double bond repels more than the single bonds

          B

          [Cu(NH3)4(H2O)2]2+

          Octahedral

          90o

          The eight bonding pairs will repel each other equally

          C

          Cisplatin

          Square planar

          109.5o

          Minimises the repulsion between the electrons in the d orbitals

          * D*

          Sulfur dioxide

          Bent

          119o

          Lone pairs repel more than bonding pairs due to a higher concentration of the electron charge cloud

            Choose your answer

            4
            1 mark

            Which statement(s) is/are correct?

            1. Bromoethane is more reactive than chloroethane because bromine is less electronegative than chlorine.

            2. The C-Br bond in bromoethane requires more energy to break than the C-Cl bond in chloroethane due to the C-Br bond being more polar.

            3. The C-Br bond in bromoethane is stronger than the C-Cl bond in chloroethane due to bromine having an increased nuclear charge.

            • 1, 2 and 3

            • Only 1 and 2

            • Only 2 and 3

            • Only 1

            Choose your answer

            5
            1 mark

            Which statement(s) is/are correct?

            1. Butane and propanone have the same number of electrons so their induced dipole-dipole intermolecular forces are the same.

            2. Only glycine will dissolve in water because it has hydrogen bonding.

            3. Within a protein, glycine has one place in which a hydrogen bond could form.

            • 1, 2 and 3

            • Only 1 and 2

            • Only 2 and 3

            • Only 1

            Choose your answer