Oxidation, Reduction, and Redox Reactions ( AS )

Question 1

What is oxidation?

Answer 1

The loss of electrons

Question 2

What is reduction?

Answer 2

The gain of electrons

Question 3

What is an oxidising agent?

Answer 3

Species that gains electrons

Question 4

What is a reducing agent?

Answer 4

Species that lose electrons

Question 5

What are the half equations and the ionic equations for: SnO+Zn—>ZnO+Sn

Answer 5

Half equations:
● Sn2+ + 2e- —> Sn
● Zn —> Zn2+ + 2e-

Question 6

Define oxidation state

Answer 6

A number that represents the number of electrons lost or gained by an atom of that element in the compound

Question 7

What is the oxidation state of oxygen in OF2?

Answer 7

+2

Question 8

What is the oxidation state of hydrogen in KH?

Answer 8

-1 (metal hydrides only)

Question 9

What is the oxidation state of chlorine in NaClO?

Answer 9

+1

Question 10

Define the term disproportionation reaction?

Answer 10

A redox reaction where oxidation and reduction occurs to the same species

Question 11

What is the oxidation state of phosphorus in PCl5?

Answer 11

+5

Question 12

What is the oxidation state of nitrogen in ammonia?

Answer 12

-3

Question 13

What is the oxidation state of arsenic in AsO4 3-

Answer 13

+5

Question 14

What is the oxidation state of iron in K4Fe(CN)6?

Answer 14

+2

Question 15

What happens in a redox reaction?

Answer 15

● electrons are transferred from one species(element) to another
● one element is oxidised whilst another is reduced

Question 16

Why is 2CrO4 2- +2H+ —> Cr2O7 2- + H2O not a redox reaction?

Answer 16

Chromium and hydrogen have the same oxidation state( no element is reduced and oxidised)