CAIE A-Level Chemistry AS 3 Chemical Bonding Questions

Practise explaining ionic, covalent, coordinate and metallic bonding and relating structure to shape and properties.

Covered syllabus points

3.1 Electronegativity and bonding 3.2 Ionic bonding 3.3 Metallic bonding 3.4 Covalent bonding and coordinate (dative covalent) bonding 3.5 Shapes of molecules 3.6 Intermolecular forces and bond properties 3.7 Dot-and-cross diagrams

[Maximum number: 9]

The melting points of some solids are shown in Table 1.1.

Table 1.1

(a)

State the type of bonding present in magnesium and in sodium chloride. bonding in magnesium
bonding in sodium chloride

[ 1 ]

(b)

Define electronegativity.

[ 1 ]

(c)

Explain why electronegativity increases across a period.

[ 2 ]

(d)

Name the strongest intermolecular force that exists between $\mathrm{NH}_{3}(\mathrm{I})$ molecules.

[ 1 ]

(e)

Draw a diagram to show the formation of the strongest intermolecular force between two molecules of $\mathrm{NH}_{3}(\mathrm{I})$ .

Include any relevant lone pairs of electrons and dipoles.

[ 2 ]

Correct hydrogen-bond diagram can be represented as:
${}^{\delta-}\mathrm{N}-{}^{\delta+}\mathrm{H}\cdots{}^{\delta-}\mathrm{N}$

{}^{\delta-}\mathrm{N}-{}^{\delta+}\mathrm{H}\cdots{}^{\delta-}\mathrm{N}

Accept the reverse orientation:
${}^{\delta+}\mathrm{H}\cdots{}^{\delta-}\mathrm{N}-{}^{\delta+}\mathrm{H}$

Marking points:
M1 link shown as a dashed line between the lone pair of electrons from N of one $\mathrm{NH}_{3}$ molecule to one H on another $\mathrm{NH}_{3}$ molecule.
M2 minimum 3 correct partial charges on adjacent atoms over two $\mathrm{NH}_{3}$ molecules.

(f)

The melting points of ice and ammonia are shown in Table 1.2.

Table 1.2

Suggest two reasons for the difference in the melting points of ice and ammonia.

[ 2 ]

[Maximum number: 1]

Copper has a high melting point.
What is the reason for the high melting point of copper?

strong attractive forces between copper atoms only

strong attractive forces between copper ions and delocalised electrons

strong attractive forces between copper ions only

strong attractive forces between copper atoms and delocalised electrons

[Maximum number: 1]

When solid aluminium chloride is heated, $\mathrm{Al}_{2} \mathrm{C} l_{6}$ is formed.
Which bonding is present in $\mathrm{Al}_{2} \mathrm{Cl}_{6}$ ?

covalent and coordinate (dative covalent)

covalent only

ionic and coordinate (dative covalent)

ionic only

[Maximum number: 1]

Which shape is correctly predicted by VSEPR theory?

number of bonded electron pairs

number of lone pairs

shape

linear

tetrahedral

pyramidal

trigonal planar

All question bank results loaded

Covered syllabus points

Question 1

Question (a)

Question (b)

Question (c)

Question (d)

Question (e)

Question (f)

Question 2

Question 3

Question 4