Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry A Level > General > Flashcards

General Flashcards

1
Q

What is an electron density map?

A

X ray diffraction from ionic solids

Remember: the cation can distort the electron field of the anion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does ionic bond strength depend on?

A

Charge density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does charge density depend on?

A
  • charge of jon

* radius of ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Evidence for ions

A
  • high melting and boiling point -> presence of bonds
  • conduct -> charged particles that are free to move
  • ion migration in electrolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sigma bond

A

Lies symmetrically along an axis joining two nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pi bind

A

Forms alongside the atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Electron density of covalent substances

A

Even

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Expanding the octet

A

And atom splits a pair
Takes energy
Enough energy is paid off in the making of the bond
2nd period do not do it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What changes the shapes of ions?

A

Electron fields move to minimise repulsion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Electronegatibity

A

The ability of an atom to attract the shared pair of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Polarisation

A

Distortion of the electron regions due to different electro negativities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens when a substance has a polar bond

A

Gives covalent structures ionic qualities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How to decide whether a molecule is polar

A

Look at the charge centres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Polar molecule

A

Has partial charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Dipole

A

Separation of partial charges

Causes dipole-dipole attractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Evidence for London forces

A

When noble gases are fooled enough the fondnesne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do LONDON forces arise

A

Electron imbalance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Hydrogen bindings

A

Leaves the hydrogen proton exposed Lone pair attracted to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Boiling points of allâmes

A

Increase with molecular mass

Branching causes decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hydration of Ito s

A

Water molecules linkig

Vibrating water molecules shake the ions free from the lattice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Bent

A
  • 2 bonding pairs
  • 1 lone pair
  • bond angle less that 120

Or
• 2
• 2
• 104.5

22
Q

Tetrahedral

A

• 4 bonding
• 0 lone
•
109.5

23
Q

Trigonal pyramidal

A
  • 3 bonding
  • 1 lone
  • 107.5
24
Q

Trigonal bipyramindal

A

• 5
• 0
• 120
90

25
Octahedral
* 6 * 0 * 90
26
Barium combustion
Green flame | Perioxide (BaO2)
27
Group 2 reactivity
Less reactive with water than corresponding group 1 | Beryllium does not react with stream
28
Metal oxide + water
Metal hydroxide Except beryllium oxide
29
Sulfate solubilité
Decreases down the group
30
Hydroxide solubility
More soluble down the group Calcium carbonate much less soluble than calcium hydroxide
31
Carbonate decomposition
All group 1 do it at skl Thermal stability increases down the group
32
Explanation of carbonate
* greater charge density in cation * greater distortion on anion * draws oxygen towards it, weakens C-O bind * vibrational energy breaks bond * as cations get larger, polarising power decrease * group 1 less than group 2
33
Nitrate decomposition
All do it Group 1 except Li -> metal nitrite + oxygen Li + group 2, more polarisaient -> metal oxide + nitrogen dioxide + oxygen
34
Nitrite
NO2-
35
Flame colours
Calcium brick red Strontium crimson Barium green
36
Halogens as oxidising agent
Chlorine is strongest Iodine is weakest Because chlorine takes up electrons the most easily
37
Halogen + sodium
Burn vigorously in chlorine | React with others but less exothermic
38
Chlorine + hydrogen
Explodes in the presence of sunlight
39
Chlorine + water ->
HOCl + HCl
40
Chlorine + cold soidym hydroxide ->
NaOCl + NaCl
41
Chlorine + hot sodium hydroxide ->
NaClO3 + 5NaCl
42
Chlorine water + iron(II) solution
Goes from green to yellow Solution of Fe3+ is formed Cl2 + 2Fe2+ -> 2Cl- + 2Fe3+ Bromine can, idoine can’t
43
Potassium halide + concentrated sulphuric acid
• hydrogen halide + other substance
44
KCl + H2SO4 ->
HCl KHSO4 - steamy white fumes Chlorine not strong enough reducing agent to react further
45
Describe concentrated sulfur if acid
Oxidising agent
46
Bromide + conc H2SO4
Orange steamy fumes -> Br2 + 2H2O + SO2
47
Iodide + conc H2SO4
Sulfur dioxide, iodine, hydrogen sulfure
48
Reducing agent
Chlorine is weakest Iodine is stronger Gives away its outer electron most easily
49
Hydrogen halides
Soluble Dissociate in water Forms acidic solution
50
Ammonia + hydrogen halide
Dense white smoke of ammonium halide is produced
51
What happens when a bond forms?
One electron from each atom enters a cloud of lower energy
52
Average bond enthalp
Calculated in the gaseous state Innacfutaye because environment affects bond

Chemistry A Level (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions