Ionic compounds

Question 1

How are ions formed?

Answer 1

Ions are formed when atoms lose or gain electrons to obtain the stable electron arrangement of a noble gas.

Question 2

Describe ion-electron equations that show the formation of ions through loss or gain of electrons

Answer 2

An ion-electron equation shows the number of electrons lost on the right-hand side and the number of electrons gained on the left-hand side.

Question 3

Give the definition for an ionic bond

Answer 3

An ionic bond is an electrostatic attraction between oppositely charged ions.

Question 4

Describe the structure of an ionic compound

Answer 4

An ionic substance consists of a lattice structure of oppositely charged ions with each positive ion surrounded by negative ions, and vice versa.

Question 5

Explain why ionic compounds have high melting points

Answer 5

Ionic compounds have high melting and boiling points because lots of energy is needed to break the strong ionic bonds in the lattice.

Question 6

State what happens to the ionic lattice when an ionic compound dissolves in water or is melted

Answer 6

As they dissolve, the lattice structure breaks up allowing water molecules to surround separated ions. The ions are now free to move.

Question 7

Explain why ionic compounds do not conduct in the solid state but do when molten or in solution

Answer 7

Ionic compounds do not conduct in the solid-state because the ions are not free to move, as they are held rigidly in the crystal lattice by strong ionic bonds.

Question 8

What are ions attracted to during the conduction of an ionic solution or melt

Answer 8

The ions move to oppositely charged electrodes. Positive ions move towards the negative electrode and vice versa. This is called electrolysis.

Question 9

Name the non-metal that is used as electrodes in conductivity apparatus for liquids

Answer 9

The electrodes are made of carbon in the form of graphite because graphite conducts electricity.