3.1.7 - Oxidation, reduction and redox equations

Question 1

what is oxidation

Answer 1

loss of electrons

Question 2

what is reduction

Answer 2

gain of electrons

Question 3

what is a redox reaction

Answer 3

a reaction where reduction and oxidation happen simultaneously

Question 4

what is an oxidising agent

Answer 4

oxidising agent accepts electrons and gets reduced

Question 5

what is a reducing agent

Answer 5

reducing agent donates electrons and gets oxidised

Question 6

what does oxidation state tell you

Answer 6

oxidation state of an element tells you the total number of electrons it has donated or accepted

Question 7

what are oxidation states also known as

Answer 7

oxidation numbers

Question 8

oxidation states of uncombined elements

Answer 8

uncombined elements have oxidation state of 0

Question 9

oxidation states of elements just bonded to identical atoms

Answer 9

elements just bonded to identical atoms have oxidation state of 0

Question 10

oxidation states of simple monoatomic ions

Answer 10

oxidation states of simple monoatomic ions is the same as its charge

Question 11

oxidation states of simple monoatomic ions example Na1+

Answer 11

e.g. Na1+ has oxidation state +1

Question 12

what is overall oxidation state equal to

Answer 12

overall change on the ion

Question 13

oxidation states in compound ions

Answer 13

most electronegative element has a negative oxidation state (equal to its ionic charge)

Question 14

what is usually the oxidation state of H

Answer 14

+1, except when bonded to a metal, metal must have positive oxidation number

Question 15

what is usually the oxidation state of O

Answer 15

-2, except when bonded to F or in peroxides , F must have the negative oxidation number

Question 16

increase in oxidation number

Answer 16

increase in oxidation number = oxidation

Question 17

decrease in oxidation number

Answer 17

decrease in oxidation number = reduction

Question 18

steps in redox equations
step 1

Answer 18

assign oxidation states, tells us what is reduced and oxidised

Question 19

steps in redox equations
step 2

Answer 19

balance the elements with changing oxidation states

Question 20

steps in redox equations
step 3

Answer 20

add electrons as needed in order to change the oxidation state (charge must balance)

Question 21

steps in redox equations
step 4

Answer 21

add H2O to balance oxygen

Question 22

steps in redox equations
step 5

Answer 22

add H+/OH- to balance hydrogen

Question 23

ammonium ion

Answer 23

NH4 +

Question 24

carbonate ion

Answer 24

CO3 2-

Question 25

hydroxide ion

Answer 25

OH -

Question 26

nitrate ion

Answer 26

NO3 -

Question 27

sulphate ion

Answer 27

SO4 2-

Question 28

sulphite ion

Answer 28

SO3 2-