2.1.5: Redox

Question 1

All uncombined elements have an oxidation number of

Answer 1

0

Question 2

The sum of oxidation numbers in a neutral compound is

Answer 2

0

Question 3

The oxidation number of a monatomic ion =

Answer 3

the charge of the ion

Question 4

The oxidation number of a polyatomic ion =

Answer 4

sum of all the oxidation numbers

Question 5

The oxidation number of F in compounds =

Answer 5

-1

Question 6

Oxidation numbers of H

Answer 6

• +1 with non-metals

* -1 wih metals, bismuth and silicon

Question 7

Oxidation numbers of O

Answer 7

-2 in compounds except:
• in F₂O where = +2
• in peroxides where = -1
• in superoxides where = -1/2

Question 8

OIL RIG

Answer 8

Oxidation
Is
Losing electrons

Reduction
Is
Gaining electrons

Question 9

Oxidising agent can be seen as

Answer 9

electron acceptor because it is itself reduced

Question 10

Oxidation state

Answer 10

Chemical accounting for the degree of oxidation of an element or compound.

Question 11

When working out oxidation states, split up

Answer 11

only IONIC compounds, not parts of molecules.

Question 12

Redox reaction

Answer 12

both reduction and oxidation occur.
Electrons are lost and gained.
Oxidation numbers go up and down.

Question 13

How do oxidation numbers change for reduction?

Answer 13

Decrease in oxidation number = reduction (electrons gained)

Question 14

How do oxidation numbers change for oxidation?

Answer 14

Increase in oxidation number = oxidation (electrons lost)