Oxidation & Reduction (chpt. 14)

Question 1

Oxidation ( in terms of electrons )

Answer 1

Oxidation of an element takes place when it loses electrons

Question 2

Reduction ( in terms of electrons )

Answer 2

Reduction of an element takes place when it gains electrons

Question 3

Oxidising agent

Answer 3

A substance that brings about oxidation in other substances

i.e. the substance that is REDUCED is the OX. agent

Question 4

Reducing agent

Answer 4

A substance that brings about reduction in other substances

i.e. the substance that is OXIDISED is the RED. agent

Question 5

Oxidation number

Answer 5

The charge that an atom has or appears to have when electrons are distributed according to certain rules

Question 6

Oxidation number of an element

Answer 6

Always 0

Question 7

Oxidation number of an ion

Answer 7

The charge an ion has

Question 8

Oxidation number of a compound

Answer 8

0 (unless there’s a charge)

Question 9

Oxidation number of oxygen

Answer 9

-2 (except peroxide = -1 & fluorine = -2)

Question 10

Oxidation number of hydrogen

Answer 10

+1 (except metals = -1)

Question 11

Oxidation number of halogens

Answer 11

-1 (except more electronegative = +1)

Question 12

Oxidation number of complex ions

Answer 12

The charge on the ion

E.g. SO 2- Charge is -2
4

Question 13

BALANCE EQUATIONS USING OXIDATION NUMBERS

Question 14

Oxidation in terms of oxidation numbers

Answer 14

Increase in oxidation number

Question 15

Reduction in terms of oxidation numbers

Answer 15

Decrease in oxidation number

Question 16

Oxidation number

Answer 16

The charge that an atom has or appears to have when electrons are distributed according to certain rules