2.1.5 Redox

Question 1

What is a redox reaction?

Answer 1

Transfer of e- between 2 species

Question 2

OILRIG?

Answer 2

Oxidation is Loss

Reduction is Gain

Question 3

What is an oxidising agent?

Answer 3

Gains electrons and is reduced

Reduced = Oxidising agent

Question 4

What is a reducing agent?

Answer 4

Loses electrons and is oxidised

Oxidised = Reducing agent

Question 5

How do you find which species has been oxidised/ reduced?

Answer 5

1. Write oxidation numbers on both halves

2. See difference and use OILRIG

Question 6

Oxidation number rules: uncombined elements? e.g. O2

Answer 6

0

Question 7

Oxidation number rules: ions?

Answer 7

Same as charge

Question 8

Oxidation number rules: group 1?

Answer 8

+1

Question 9

Oxidation number rules: group 2?

Answer 9

+2

Question 10

Oxidation number rules: aluminium?

Answer 10

+3

Question 11

Oxidation number rules: hydrogen?

Answer 11

+1

Except hydrides: -1

Question 12

Oxidation number rules: chlorine?

Answer 12

-1

Except with F/0: +x

Question 13

Oxidation number rules: fluorine?

Answer 13

-1

Question 14

Oxidation number rules: oxygen?

Answer 14

-2
Except in peroxides: -1
Except with F: +2

Question 15

The oxidation numbers of a compound must add up to _______

Answer 15

The overall charge of the molecule

Question 16

How are elements with different oxidation numbers shown?

Answer 16

Roman numerals

e.g. Chlorate (III)

Question 17

What happens when a s, p, d-block metal reacts with an acid? (2)

Answer 17

–> Salt + Hydrogen Gas

Acid is oxidised (O –> +x)