L7: Ionic Bonding Flashcards Preview

Chemistry (Semester 1) > L7: Ionic Bonding > Flashcards

Flashcards in L7: Ionic Bonding Deck (22):
1

What is the octet rule?

Most atoms show a tendency to adjust their valence shells to 8 e- by losing, gaining, or sharing electrons

2

What is the most notable exception to the octet rule?

Transition metals using d-orbitals obey the 18 electron rule instead

3

What is the most electronegative element?

Fluorine - small, high nuclear charge

4

True or false: Electronegativity increases across a period, and decreases down a group

True

5

True or false: Ionic bonding involves the sharing of electrons between atoms

False. In ionic bonding one or more electron is fully transferred between atoms

6

True or false: Ionic bonding takes place between metals and non-metals

True

7

True or false: Forming an ionic bond involves a decrease in energy compared to the two isolated atoms

True

8

True or false: Ionic bonds are directional

False

9

True or false: Ionic compounds disassociate in polar solvents, such as water

True

10

True or false: Ionic compounds have an overall charge

False. Ionic compounds are neutral

11

True or false: Ionic bonds are broken when the compound is melted

True

12

True or false: Ionic compounds form crystalline solids with low melting temperatures

False. They form crystalline solids with HIGH melting temperatures

13

True or false: Ionic compounds conduct electricity when molten and/or in solution

True

14

What is 'lattice energy'?

The enthalpy of forming one mole of the ionic solid from its gaseous ions

15

True or false: Ionic compounds form giant lattice structures

True

16

In order to favour ionic bond formation, what electronegativity difference is needed between the cation and the anion?

The larger the better

17

True or false: To form an anion, a metal should have a low ionisation energy

False. Metals don't form the anion, they form the cation. And for cation formation, a low ionisation energy is favourable.

18

True or false: To form an anion, a non-metal should have a high electron affinity

True

19

When is an ionic compound likely to have some covalent character?

When (a) the cation is small and/or has a high charge; or, (b) the anion is large and/or has a high charge

20

How do ionic compounds gain some covalent character?

By polarisation - instead of being spherical, the anion loses it's shape and is pulled towards the cation

21

What are the five important cations in the body?

1) Sodium
2) Potassium
3) Calcium
4) Hydrogen
5) Magnesium

22

What are the five important anions in the body?

1) Chloride
2) Bicarbonate
3) Hydrogenphosphate
4) Sulphate
5) Phosphate