3.1 Ionisation Energy

Question 1

First ionisation energy of an element is

Answer 1

The energy required to remove one electron from each atom in one mole of the gaseous element to form one mole of gaseous 1+ ions

Question 2

Disproportionation

Answer 2

Is the oxidation and reduction of the same element in a redox reaction

Question 3

3 factors affecting ionisation energy

Answer 3

Atomic radius
Nuclear charge
Electron shielding

Question 4

2nd ionisation energy of Li

Answer 4

Li+(g) –> Li2+ + e-

Question 5

Decrease in IE between group 12 to 13

Answer 5

Group 13 outermost electron in p-orbital, while Group 2 outermost electron in s-orbital. P-orbitals have slightly higher energy than s-orbitals, so electrons further away from nucleus. This makes electrons in p-orbitals easier to remove than in s-orbitals.

Question 6

Decrease in IE between group 15 and 16

Answer 6

In Groups 13, 14, and 15 each p-orbital contains only one electron. In Group 16, outermost electron is spin-paired with another electron. This means the electron experiences some repulsion and makes the outer electron easier to remove.

Question 7

Large increases in successive IE reflect…

Answer 7

Jump from one shell to another closer to the nucleus