4.1 Ionic Bonding And Structure

Question 1

What are the outer most electrons of an atom called?

Answer 1

Valence electrons

Question 2

How does an atom change when it forms an ionic bond?

Answer 2

The becomes an ion with an overall charge because it’s gained or lost and electron

Question 3

What is a cation?

Answer 3

An atom which has lost an electron from its outer shell and become a positive ion

Question 4

What is an anion?

Answer 4

An atom which has gained electrons in its outer shell in order to form a negative ion

Question 5

Give examples of polyatomic ions!

Answer 5

Nitrate
Hydroxide
Hydrogen carbonate 
Carbonate
Sulphate
Phosphate
Ammonium

Question 6

Electrons from the …….. Tend to be transferred To the ……….

Answer 6

Electrons from the metal tend to be transferred to the non metal

Question 7

What is an ionic bond?

Answer 7

The electrostatic attraction between two oppositely charged ions (neutral compound)

Question 8

What structure do ionic compounds have?

Answer 8

Lattice structure because the electrostatic attraction causes the ions to surround themselves with the oppositely charged ions forming a 3D CRYSTALLINE STRUCTURE

Question 9

What is lattice energy?

Answer 9

A measure of the strength of attraction between the ions with in a lattice

Question 10

What kind of boiling and melting points do ionic compounds tend to have?

Answer 10

High melting and boiling points because the electrostatic attractions are very strong, therefore require a large amount of energy to break

Question 11

What is coordination number?

Answer 11

The number of ions that surround one ion within a lattice

Question 12

Do ionic compounds have a low or high volatility?

Answer 12

Low

Question 13

Are ionic compounds soluble?

Answer 13

They are generally soluble in ionic or polar solvents but are insoluble in non-polar solvents

Question 14

What happens when an ionic compound is added to water?

Answer 14

The partial charges of the hydrogen and oxygen in the water molecules will be attracted to the ion of the opposite charge. This pulls the ions away and separates them from the lattice and the ions become surrounded by water molecules a.k.a hydrated

Question 15

Can ionic compounds carry charge in the solid state?

Answer 15

No because there are no delocalised ions which can carry charge through the compound

Question 16

Can ionic compounds carry charge in the liquid or aqueous state?

Answer 16

Yes because the ions are able to move around and therefore carry an electrical charge through the substance

Question 17

How can we predict the tendency of an ionic bond?

Answer 17

Looking at the electro-negativity values and seeing if there is a large difference between them. If so the electrons will be pulled more towards one atom giving it full control of the electrons making it an ionic bond.

Question 18

Why are ionic compounds brittle?

Answer 18

Because the movement is forcing charged ions against each other which increases the repulsion between the positive nuclei’s and causes the substance to split.

Question 19

Explain what happens to the electron configurations of Mg and Br when they react to form the compound magnesium bromide

Answer 19

The magnesium atom loses two electrons from its 3s orbital and the two bromine atoms gain one electron into their 4p sub shell. These two ions then attract each other by electrostatic forces and form a lattice.

Question 20

Which fluoride is the most ionic?

NaF. CsF. MgF2. BaF2.

Answer 20

CsF because it has the greatest difference in electronegativity values

Question 21

How could you test if something was an ionic compound?

Answer 21

Test its:
Melting point - would be very high
Solubility - dissolve in polar substances
Conductivity - they are good conductors in aqueous solutions

Question 22

What charge do all atoms have? And why?

Answer 22

Neutral, because the protons and electrons cancel their +1 charges out and the neutrons have no charge