U3-1-2 - Redox Reactions

Question 1

Redox reaction

Answer 1

A reaction involving a transfer of electrons.

(One reactant loses electrons, the other gains them)

Question 2

Loss of electrons

Answer 2

Oxidation

(remember - OIL RIG)

Question 3

Gain of electrons

Answer 3

Reduction

(remember - OIL RIG)

Question 4

Oxidation

Answer 4

Loss of electrons

(rememeber - OIL RIG)

Question 5

Reduction

Answer 5

Gain of electrons

(rememeber - OIL RIG)

Question 6

How do you turn this reduction equation into an oxidation equation?

Cu²⁺ + 2e^– → Cu

Answer 6

Reverse it

Cu → Cu²⁺ + 2e^–

Question 7

When copying equations from the ECS, which equation gets reversed?

Answer 7

The one higher up in the ECS

OR read equations anticlockwise

Question 8

What has to be done before these equations can be added up?

Answer 8

Electrons must be balanced

(so multiply whole Na equation by 2)

Question 9

What type of reaction is this?

MgO + H₂SO₄ → MgSO₄ + H₂O

Answer 9

Neutralisation

(base + acid)

Question 10

What type of reaction is this?

C₂H₄ + Br₂ → C₂H₄Br₂

Answer 10

Addition

(multiple reactants, only one product)

Question 11

What type of reaction is this?

3Na(s) + AlCl₃(aq) → 3NaCl(aq) + Al(s)

Answer 11

Displacement

(Na displaces Al from a compound)

Question 12

What type of reaction is this?

Li(s) + HCl(aq) → LiCl(aq) + H₂(g)

Answer 12

Redox

(Li loses electrons, H⁺ gains electrons)

NOT neutralisation as no water is made

Question 13

What type of reaction is this?

AgNO₃(aq) + KCl(aq) → AgCl(s) + KNO₃(aq)

Answer 13

Precipitation

(solid, AgCl, is formed from aqueous reactants)

Question 14

What is wrong with this redox equation?

Cu²⁺ + Ag + e^– → Cu + Ag⁺

Answer 14

Still has e^–

(Electrons were not balanced before adding up equations)