Thermo Chem

Question 1

Across a row

Answer 1

Ionisation energy increases
, due to increasing electrostatic attraction across a group

Question 2

Down a group

Answer 2

Ionisation energy decreases, due to decreasing electrostatic attraction

Question 3

Atomic radius across a row

Answer 3

Decreases, as electrons are pulled in closer due to electrostatic attraction

Question 4

Atomic radius down a group

Answer 4

Increases as weaker electrostatic attraction, electrons aren’t pulled in close

Question 5

Across group..

Answer 5

Protons increase, no change in shielding or distance

Question 6

Down group

Answer 6

Number of protons but distance from nucleus increases and shielding increases

Question 7

2 electron pairs, 1 bonded

Answer 7

Linear

Question 8

2 pairs, 2 bonden

Answer 8

Linear 180

Question 9

3, 1 bonded

Answer 9

Linear 180

Question 10

3, 2 bonded

Answer 10

Bent 109.5

Question 11

3,3 bonded

Answer 11

Trigonaal planar 120

Question 12

4,1 bonded

Answer 12

Linear 180

Question 13

4,2 bonded

Answer 13

Bent 109.5

Question 14

4,3 bonded

Answer 14

Tribunal pyramidal 109.5

Question 15

4,4

Answer 15

Tetrahedral 109.5

Question 16

5,3

Answer 16

T shsped 90

Question 17

5,4

Answer 17

Seesaw 120

Question 18

5,5

Answer 18

Trigonal bipyramidal 120

Question 19

6,4

Answer 19

Square planar 90

Question 20

6,5

Answer 20

Square pyramid 90

Question 21

6,6

Answer 21

Octahedral 90

Question 22

Exothermic

Answer 22

Gives out heat, makes bonds -

Question 23

Endothermic,

Answer 23

Requires heat, breaks bond +

Question 24

Fusion

Answer 24

Solid- liquid

Question 25

Vapourisation

Answer 25

Liquid gas

Question 26

Sublimation

Answer 26

Solid to gas

Question 27

Combustion

Answer 27

With oxygen

Question 28

Entropy

Answer 28

Measure of disorder in system

Question 29

Flat line represents

Answer 29

State change, temp is used to break bonds and stays same- as does kinetic energy

Question 30

Climb in graph shows

Answer 30

Temp and kinetic energy increasing

Question 31

+ve entropy

Answer 31

=Spontaneity

Question 32

An - ion -affect on radius

Answer 32

Gains an electron, to become ion. This increases electron repulsion in valence energy level. Causes them to move further away so radius increases

Question 33

Ionisation energy

Answer 33

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

Question 34

Electronegativity

Answer 34

Ability of an atom in a bond to attract electrons to itself

Question 35

Common ion effect

Answer 35

Solubility of one salt is reduced by the presence of having another common ion

Question 36

Buffer solution

Answer 36

Resists changes in ph when oh and h30 are added

Question 37

Covalent bond

Answer 37

A shared pair of electrons, one electron being supplied by each atom- either side of the bond

Question 38

Ionic bond

Answer 38

Oppositely charged ions held together by a crystal lattice by electrostatic attraction

Question 39

Metallic bonding

Answer 39

Lattice of positive ions surrounded by delocalised electrons

Question 40

Going down up group ionisation energy

Answer 40

Going up a group the number of energy levels decreases, as doe’s repulsion from inner energy levels. Valence electrons are closest to positive nucleus, this means there is a string electrostatic attraction between the positive nucleus and bonded valence shells- therefore most electronegative

Question 41

Change in fusion enthalpy

Answer 41

Enthalpy change with 1 mol of substance is formed with its elements in standard state

Question 42

Enthalpy combustion

Answer 42

Enthalpy change when one mol of substance is completely burned with oxygen

Question 43

Atomic radius left to right

Answer 43

As the atomic number increases, so does the number of protons (therefore the positive charge in the nucleus). The electron shells are pulled in with more force, therefore there’s a strong electrostatic attraction between the positive nucleus and valence electrons. Therefore the atomic radius decreases

Question 44

Atomic radius as you go down a group

Answer 44

The number of energy levels increase, and therefore the repulsion of the valence energy levels increase too. This causes the valence electrons to be further away from the nucleus and aren’t as strongly attracted by the increasing number of protons, so electrostatic attraction decreases and radius increases

Question 45

Ionisation energy across a group

Answer 45

Increases as the number of protons increase, so there’s a greater nuclear charge attracting the orbiting electrons doing so strongly, therefore more energy is required to overcome this energy

Question 46

Alcohol is it polar

Answer 46

Yes

Question 47

Is a ketone/ aldehyde polar

Answer 47

Yss

Question 48

Why is change in vap bigger than change in fusion

Answer 48

More heat energy is required to break all the attractive forces between liquid particles to form a gas. When a solid changes into a liquid, only some of the attractive forces are overcome, so less heat energy is required