B2 Redox + Periodicity

Question 1

Oxidation number of element

Answer 1

0

Question 2

Oxidation number of group 1

Answer 2

1+

Question 3

Oxidation number of group 2

Answer 3

2+

Question 4

Oxidation number of flourine

Answer 4

1-

Question 5

Oxidation number of oxygen in H2O2

Answer 5

1-

Question 6

Oxidation number of hydrogen in H2O2

Answer 6

1+

Question 7

What substance gets the negative oxidation number in a compound

Answer 7

The most electronegative

Question 8

Sum of oxidation numbers in a compound

Answer 8

0

Question 9

Sum of oxidation numbers in an ion

Answer 9

Charge of ion

Question 10

What happens to oxidation number when a substance is reduced

Answer 10

Decreases

Question 11

What happens to oxidation number when a substance is oxidised

Answer 11

Increases

Question 12

When writing systamatic names, when does the Roman numeral oxidation number come

Answer 12

• In brackets after the element
• e.g Titanium (IV) Oxide

Question 13

In metal and acid reactions, what is reduced and what is oxidised

Answer 13

• Metal oxidised
• Hydrogen reduced

Question 14

Meaning of oxidation

Answer 14

• Loss of electrons
• Increase in oxidation number

Question 15

Meaning of reduction

Answer 15

• Gain of electrons
• Decrease in oxidation number

Question 16

Define Disproportionation

Answer 16

Reduction and oxidation of the same element in the same reaction

Question 17

Define Oxidising Agent

Answer 17

• Removes electrons from another species buy accepting them
• Increasing species oxidation number

Question 18

Define Reducing Agent

Answer 18

• Donates electrons to another species by loosing them
• Decreasing species oxidation number

Question 19

How to write elemental half-equations

Answer 19

• Calculate overall charge on each side
• Add electrons to more positive side
• Ensure fully balanced

Question 20

How is the periodic table arranged

Answer 20

Increasing atomic number

Question 21

How to write half-equations for acidic conditions

Answer 21

• Balance the element changing oxidation state
• For every oxygen, add an H2O to the other side
• For every hydrogen, add an H+ to the other side
• Use electrons to ensure both sides have the same charge

Question 22

What do elements in periods in the periodic table have

Answer 22

Repeating trends in physical and chemical properties

Question 23

What do elements in groups of the periodic table have

Answer 23

Similar chemical properties

Question 24

Define Periodicity

Answer 24

The repeating trends in physical and chemical properties across different periods

Question 25

How to explain why an element is in the s/d/p block

Answer 25

It's highest energy electron is in the s/d/p subshell

Question 26

Define First Ionisation Energy

Answer 26

The energy required to remove 1mol of electrons from 1mol of gaseous atoms

Question 27

How to explain differences in ionisation energies

Answer 27

* Electron shells * Atomic radius * Sheilding * Nuclear charge * Sheilding + atomic radius *outweigh* nuclear charge * Nuclear attraction

Question 28

What must always be stated when describing changes in ionisation energies

Answer 28

Sheilding - even if has no effect

Question 29

When given an ionisation energy graph for an element, how can you tell what group that element is in

Answer 29

* Greatest jump in ionisation energies * Jump 4 - 5 * In group 4

Question 30

General equation for first ionisation energy

Answer 30

Question 31

General equation for second ionisation energy

Answer 31

Question 32

Draw a graph for ionisation energies across period 2

Answer 32

Question 33

What element has highest first ionisation energy

Answer 33

Helium

Question 34

On first ionisation energy graphs, there is a general increase - what are the exceptions

Answer 34

* New shell - decrease * p subshell - decrease * group 6 - decrease (new electron in singular paired orbital so more repulsion)