2.3 - Ionic Compounds

Question 1

Metals normally form ions which have a ______ charge, while non-metals form ions with a ______ charge.

Ions are attracted to other ions with the opposite charge, due to ______ forces.

Answer 1

Metals normally form ions which have a positive charge, while non-metals form ions with a negative charge.

Ions are attracted to other ions with the opposite charge, due to electrostatic forces.

Question 2

Ionic structures involve many ions bonded together via ______ bonds.

The solid arranges itself into a regular 3D structure known as a ______ .

Answer 2

Ionic structures involve many ions bonded together via ionic bonds.

The solid arranges itself into a regular 3D structure known as a lattice.

Question 3

Select three properties that ionic compounds have:

1. Conduct electricity when solid
2. High melting and boiling points
3. Conduct electricity when liquid
4. Low melting and boiling points
5. Weak strength bonds
6. High strength bonds

Answer 3

2. High melting and boiling points, 3. Conduct electricity when liquid, 6. High strength bonds

Question 4

Why can ionic compounds only conduct electricity when in liquid/molten, or aqueous form?

Answer 4

The ions are free to move and carry charge

In order for a material to conduct electricity, it must have charged particles (like electrons or ions) that are free to flow through the structure.

Question 5

strong / weak / high / low / energy / water

Ionic compounds have relatively ______ melting and boiling points.

This is because ionic bonds are very ______, and a high amount of ______ is required to break the bonds.

Answer 5

Ionic compounds have relatively high melting and boiling points.

This is because ionic bonds are very strong, and a high amount of energy is required to break the bonds.

Question 6

Select the correct formula for the ionic compound potassium chloride:

1. K₂Cl
2. KCl
3. NaCl
4. KCl₂

Answer 6

2. KCl

Question 7

Select the correct formula for a nitrate ion:

1. N3-
2. NO3
3. NO3+
4. NO3-

Answer 7

4. NO3-

Question 8

Potassium ions and carbonate ions can form an ionic compound.

Potassium ions have a ______ charge, while carbonate ions have a ______ charge.

This means every carbonate ion will ionically bond with ______ potassium ions.

Answer 8

Potassium ions and carbonate ions can form an ionic compound.

Potassium ions have a 1+ charge, while carbonate ions have a 2- charge.

This means every carbonate ion will ionically bond with 2 potassium ions.

Question 9

What is the chemical formula for the compound calcium sulfate?

1. Ca2SO4
2. Ca(SO4)2
3. CaSO4 2+
4. CaSO4

Answer 9

4. CaSO4

Question 10

What are the formulae for the ions:

Hydroxide:
Sulphate:
Nitrate:
Carbonate:
Ammonium:

Answer 10

Hydroxide: OH -
Sulphate: SO4 2-
Nitrate: NO 3-
Carbonate: CO3 2-
Ammonium: NH 4+

Question 11

What is an ionic compound?

Answer 11

A compound containing positive and negative ions, held together by electrostatic attraction

Question 12

What is a ball and stick diagram?

Answer 12

A ball and stick diagram is a way of representing molecules or compounds, in which the atoms (or ions) are represented by balls, and bonds are represented by lines or sticks between them

Question 13

Why are ball and stick diagrams not realistic?

Answer 13

1. Atoms (or ions) are not really perfect spheres
2. They don’t show the electrons
3. The atoms are relatively far apart, whereas in reality they would be much closer