Lesson 2: Ionic bonding+ Properties

Question 1

What is an ionic bond?

Answer 1

• A strong bond between metal and non- metal.

Question 2

What holds positive and negative ions together to form ionic compound?

Answer 2

• Electrostatic force holds negative and positive ions.

Question 3

What structure do ionic compounds have?

Answer 3

• Giant ionic lattices. Electrostatic force of attraction acts in all directions between oppositely- charged ions.

Question 4

What is a giant ionic lattice?

Answer 4

• A giant ionic lattice is a large, repeating structure made of oppositely charged ions.

Question 5

Give 1 P and N of ball and stick models.

Answer 5

P: show repeating pattern in all directions (not just surface)
N: spaces between ions suggests gas.

Question 6

Give 1 P and N of 3D space- filled models.

Answer 6

A: Shows how close ions are
D: Only illustrates outermost layer of compound.

Question 7

Give 1 P and N of 2D space- filled diagrams.

Answer 7

P: shows how close the ions are.
N: No idea of 3D structure.

Question 8

True or False

A salt crystal is an element that makes up a compound.

Answer 8

• False! Salt crystal is a compound that contains millions of ions.
  Crystals have a square shape from lattice structure

Question 9

What are crystals?

Answer 9

• This is the structure ionic compounds form.

IT IS A GIANT IONIC LATTICE

Question 10

What type of crystal structure do ionic compounds form?

Answer 10

• Giant ionic lattices

Question 11

What does molten mean?

Answer 11

• Means melted/ liquid

Question 12

What are the 3 properties of ionic compounds?

Answer 12

• High melting and boiling points
• Soluble
• Conduct electricity when dissolved / molten

Question 13

Why do ionic compounds have high melting and boiling points?

Answer 13

• Strong electrostatic force of attraction between positive and negative ion.
• Requires a lot of energy to break.

Question 14

Why doesn’t distilled water conduct electricity?

Answer 14

• No dissolved ions that can carry the charge/current in circuit.

Question 15

Why can’t an ionic solid conduct electricity?

Answer 15

• Ions can’t move due to strong forces of attraction in all direction.
• Ions can’t carry charge.

Question 16

Why do ionic compounds conduct when in solution/ molten?

Answer 16

• Ions are free to move/ and carry the charge (to allow current to flow)

Question 17

True or False…

In an ionic solution, the electrons move to allow charge to flow.

Answer 17

False.
- It is the ions that are moving.

Question 18

Why are ionic compounds hard?

Answer 18

1.) Have strong electrostatic forces that act in all directions.
2.) This forms lattice shape.
3.) Theses forces are hard to break.

Question 19

What is the P + N of the dot- cross diagram?

Answer 19

P: Shows where electrons come from.
N: Doesn’t give idea of shape of lattice.

Question 20

What is the empirical formula?

Answer 20

• Just the normal formula for a compound.
  BUT
• By diagram, count the ions for each element and put in simplest ratio.

Question 21

Describe the structure of NaCl

Answer 21

• Giant ionic lattice made of Na⁺ and Cl⁻.
• Opposites held by electrostatic force of attraction
• This force acts in all directions and forms giant lattice of alternating ions.

Question 22

Why do solid ionic compounds not conduct electricity?

Answer 22

• Ions can’t move due to electrostatic forces of attraction in all direction

Question 23

Q.)

Describe, in terms of electron arrangement, the type of bonding in:

(i) The compound sodium chloride

Answer 23

• Sodium outer shell = 1
• Chlorine outer shell = 7
• Sodium loses 1 electron
• Chlorine gains 1 electron
• Sodium = Na+, chlorine = Cl-
• Ions held by ionic bond

Question 24

Why do elements react?

Answer 24

• Elements react to achieve a full outer energy level.
• Have electronic structure of noble gas.

Question 25

Describe what happens when sodium reacts with chlorine (4)

Answer 25

• One electron
• Passes from sodium atom
• To chlorine atom
• Both atoms achieve a full outer- energy level.