1. States of matter

1.1 Solids, liquids and gases

1.2 Diffusion

2. Atoms, elements and compounds

2.1 Elements, compounds and mixtures

2.2 Atomic structure and the Periodic Table

2.3 Isotopes

2.4 Ions and ionic bonds

2.5 Simple molecules and covalent bonds

2.6 Giant covalent structures

2.7 Metallic bonding

3. Stoichiometry

3.1 Formulae

3.2 Relative masses of atoms and molecules

3.3 The mole and the Avogadro constant

4. Electrochemistry

4.1 Electrolysis

4.2 Hydrogen–oxygen fuel cells

5. Chemical energetics

5.1 Exothermic and endothermic reactions

6. Chemical reactions

6.1 Physical and chemical changes

6.2 Rate of reaction

6.3 Reversible reactions and equilibrium

6.4 Redox

7. Acids, bases and salts

7.1 The characteristic properties of acids and bases

7.2 Oxides

7.3 Preparation of salts

8. The Periodic Table

8.1 Arrangement of elements

8.2 Group I properties

8.3 Group VII properties

8.4 Transition elements

8.5 Noble gases

9. Metals

9.1 Properties of metals

9.2 Uses of metals

9.3 Alloys and their properties

9.4 Reactivity series

9.5 Corrosion of metals

9.6 Extraction of metals

10. Chemistry of the environment

10.1 Water

10.2 Fertilisers

10.3 Air quality and climate

11. Organic chemistry

11.1 Formulae, functional groups and terminology

11.2 Naming organic compounds

11.3 Fuels

11.4 Alkanes

11.5 Alkenes

11.6 Alcohols

11.7 Carboxylic acids

11.8 Polymers

12. Experimental techniques and chemical analysis

12.1 Experimental design

12.2 Acid–base titrations

12.3 Chromatography

12.4 Separation and purification

12.5 Identification of ions and gases

IGCSE Chemistry 2.5 Simple molecules and covalent bonds Question Bank

[Maximum number: 1]

The following table gives information about six substances.

(a)

Which substance could be propane?

[ 1 ]

[Maximum number: 5]

This question is about gases.

(a)

$\mathrm{NF}_{3}$ has covalent bonds.

[ 5 ]

(i)

What is a covalent bond?

[ 2 ]

(ii)

Complete the dot-and-cross diagram to show the electron arrangement in a molecule of $\mathrm{NF}_{3}$ .
Show outer shell electrons only.

[ 3 ]

(a)

Complete the diagram to show the electron arrangement in a carbon dioxide molecule. Show the outer shell electrons only.

[ 2 ]

[Maximum number: 2]

This question is about gases found in clean, dry air and gases found in polluted air.

(a)

Complete the dot-and-cross diagram in Fig. 1.1 for a molecule of $\mathrm{CO}_{2}$ . Show outer shell electrons only.

Fig. 1.1

[ 2 ]

[Maximum number: 1]

Ammonia, $\mathrm{NH}_{3}$ , is a covalent molecule.
Which diagram shows the outer-shell electron arrangement in a molecule of ammonia?

[Maximum number: 1]

The table shows the melting points, boiling points and electrical conductivities of six substances, D, E, F, G, H and I.

(a)

Identify the substance, D, E, F, G, H or I, which is:

[ 1 ]

(i)

a solid consisting of simple molecules at $25^{\circ} \mathrm{C}$ . ..... [1]

[ 1 ]

[Maximum number: 3]

The table shows the melting points, boiling points and electrical conductivities of six substances D, E, F, G, H and I.

Choose substances from the table which match the following descriptions. Each substance may be used once, more than once or not at all.

(a)

Which three substances contain simple molecules?

[ 3 ]

[Maximum number: 1]

Which diagram shows the arrangement of the outer shell electrons in a molecule of water?

[Maximum number: 1]

Which row describes the formation of single covalent bonds in methane?

both atoms gain a
noble gas electronic structure

both atoms have the same number
of electrons in their outer shell

both atoms gain a
noble gas electronic structure

both atoms have the same number
of electrons in their outer shell

[Maximum number: 1]

The table shows the electronic structure of four atoms.

Which two atoms combine to form a covalent compound?

W and X

W and Y

X and Y

X and Z

0 selected

Question 1

Question 1(d)

Question 1

Question 1(b)

Question 1(b)(i)

Question 1(b)(ii)

Question 1

Question 1(d)

Question 1

Question 1(h)

Question 3

Question 2

Question 2(a)

Question 2(a)(iii)

Question 2

Question 2(c)

Question 4

Question 5

Question 5