oxidation, reduction and redox equations (3.1.7) in papers 1 & 2

Question 1

what is oxidation?

Answer 1

• the loss of electrons
• shown through the increase in oxidation number.

Question 2

what is reduction?

Answer 2

• the gain of electrons.
• shown through the decrease in oxidation number.

Question 3

what is an oxidising agent?

Answer 3

• the species that gains electrons, they get reduced in the process.

Question 4

what is a reducing agent?

Answer 4

• the species that looses electrons, they get oxidised in the process.

Question 5

whats the oxidation state of group 1, 2 metals, almunium, oxygen, hydrogen, fluorine, chlorine.

Answer 5

• group 1: +1
• group 2: +2
• Al: +3
• O: -2 except in peroxides & F its -1
• H: +1 except in metal hydrides its -1
• F: -1
• Cl: -1 except with O & F

Question 6

how do you write half equations in acidic solutions?

Answer 6

• balance all the atoms except hydrogen and oxygen.
• balance the oxygens by adding h2o to the side with least amount.
• balance the hydrogens by adding H+ ions to the side with the least amount.
• balalnce charges by adding electrons to the side with the H+ ions.

Question 7

what are disproportionation reactions?

Answer 7

• when species are both oxidised and reduced.