3.1 ionic bonding

Question 1

Define ionic bonding.

Answer 1

Ionic bonding is the electrostatic force of attraction between oppositely charged ions formed by electron transfer.

Question 2

Molecular ions:

Answer 2

Hydroxide = OH^-
Nitrate = NO₃^-
Ammonium = NH₄⁺
Sulfate = SO₄^2-
Carbonate = CO₃^2-

Question 3

What ions does group 1 form?

Answer 3

Group 1 elements lose 1 electron, forming 1+ ions.

Question 4

What ions does group 2 form?

Answer 4

Group 2 elements lose 2 electrons, 2+ ions.

Question 5

What ions does group 3 form?

Answer 5

Group 3 elements lose 3 electrons, forming 3+ ions.

Question 6

What ions does group 4 form?

Answer 6

They rarely form ionic bonds, typically they form covalent bonds.

Question 7

What ions does group 5 form?

Answer 7

Group 5 elements gain 3 electrons, forming 3- ions.

Question 8

What ions does group 6 form?

Answer 8

Group 6 elements gain 2 electrons, forming 2- ions.

Question 9

What ions does group 7 form?

Answer 9

Group 7 elements gain 1 electron, forming 1- ions.

Question 10

What is an ionic compound?

Answer 10

An ionic compound is a crystalline solid that are held together by ionic bonds, which can form giant ionic lattices.

Question 11

Formulas of ionic compounds.

Answer 11

1) Write the two ions: Ca²⁺ and O^2-
2) Swap the charges: Ca^2- and O²⁺
3) Drop the charges: Ca₂ and O₂
4) Simplify to lowest whole number if needed: Ca₂O₂ simplifies to CaO

Question 12

What is the structure of an ionic compound?

Answer 12

Ionic compounds form giant ionic lattices where each ion is surrounded by oppositely charged ions.

Question 13

What are the properties of an ionic compound?

Answer 13

• Have high melting and boiling points
• They are soluble
• Can conduct electricity when molten or in solvent
• They are hard and brittle

Question 14

Why do they have high melting and boiling points?

Answer 14

The electrostatic forces holding the ionic lattice together are strong and require a lot of energy to overcome.

Question 15

How are they soluble in water?

Answer 15

The positive and negative ends of water attract the oppositely charged ions in an ionic compound allowing it to be fully dissolved.

Question 16

How can they conduct electricity when molten (melted) or when in solvent?

Answer 16

The ions are separate when molten or in solvent and are no longer held in a lattice. They are free to move and can carry a flow of charge and create an electrical current.

Question 17

Why do they not conduct electricity when solid?

Answer 17

The ions in the lattice are held in place and cannot move around to carry a charge.

Question 18

Why are they brittle?

Answer 18

When the layers of alternating charges are distorted the charges will repel therefore breaking apart the lattice into fragments.