TOPIC 3 - REDOX I

Question 1

What is oxidation?

Answer 1

Oxidation is the loss of electrons

Question 2

What is reduction?

Answer 2

Reduction is the gain of electrons

Question 3

What is a disproportionation reaction?

Answer 3

A reaction where a species is both simultaneously oxidised and reduced

Question 4

What do ionic half equations show?

Answer 4

Oxidation and reduction

Question 5

What do oxidation numbers tell you?

Answer 5

The movement of electrons

Question 6

What’s the oxidation number of any uncombined element?

Answer 6

0, e.g. O2 = 0, Cl2 = 0, C = 0

Question 7

What is the oxidation number of a simple monatomic ion?

Answer 7

The same as its charge, e.g. Na+ = +1, Mg2+ = +2

Question 8

For molecular ions, what is the sum same as the overall charge of the ion?

Answer 8

The sum of all the oxidation numbers

Question 9

What charge does hydrogen always have, except in metal hydrides?

Answer 9

Hydrogen normally has a charge of +1, except in a metal hydride where it has a charge of -1 or in H2 where it is 0

Question 10

What charge does oxygen always have, except in peroxides?

Answer 10

Oxygen normally has a charge of -2, except in a peroxide where it has a charge of -1, and molecular oxygen O2, where it has a charge of 0