Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AQA AS Chemistry > Revision > Flashcards

Revision Flashcards

1
Q

Relative atomic mass

A

Average mass of all the isotopes of an element compared to 1/12th the mass of an atom of Carbon-12

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

Steps of mass spectrometry

A

Electrospray ionisation, acceleration, ion drift, ion detector, data analysis

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

Describe electrospray ionisation

A

A sample is dissolved in a volatile solvent (water/methanol) and injected through a fine needle attached to high voltage power supply. The particle gains a proton, forming 1+ ion

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

Acceleration

A

The ion accelerated towards a negatively charged plate

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

Ion drift

A

Travel through flight tube with different velocities (because of different masses)

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

Ion detection

A

When the ion hit the plate, it gains an electron, producing a current, which is detected by the detector

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

Data analysis

A

Showing relative abundance and mass to charge ratio (m/z)

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

Why Cr has an unusual electron configuration?

A

Half-filled 3d subshells to be more stable

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

Why Fe has an unusual electron configuration?

A

Fully-filled 3d subshells to be more stable

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

Definition of isoelectronic

A

Particles with same electron configuration

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

Plum pudding model

A
  • positive pudding (not empty spaced)
  • negative electron
  • no energy shell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Covert m^3 to dm^3 and cm^3

A

1 m^3 = 1000 dm^3 = 1000000 cm^3

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

Ideal gas equation with units

A

pV= nRT
(Pa)(m^3) = (mol) (JK^-1mol^-1)(K)

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

Percentage yield

A

(Actual yield/ theoretical yield) x 100

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

Atom economy

A

(Molecular mass of desired production/ total mass of reactants) x 100

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

Why is percentage yield not 100%?

A
  • lost in transfer
  • not all reactants have fully reacted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why conical flask does not have to be fully dry?

A

Doesn’t affect the number of moles of the solute

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

Why using conical flask?

A

Easier to swirl
Prevent spitting out

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

Why placing a white tile?

A

To view the indicator colour more clearly

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

Why the funnel needed to be removed?

A

To ensure any drops remained in it do not interfere with the titre

21
Q

Percentage error (uncertainty)

A

(number of times used x uncertainty) /
Amount measured

22
Q

Ionic bond

A

Strong electrostatic attraction between oppositely charged ions held in a lattice

23
Q

Explain how Na and Cl react

A

Na atom loses its 3s electron, forming Na+ ion
Cl atom gains that electron, forming Cl- ion
Forming NaCl

24
Q

Bp and mp for ionic compounds

A

High
Because strong electrostatic attraction between oppositely charged ions

25
Q

Can ionic compounds conduct electricity?

A

Yes when molten or in aq
Ions are free to move and carry charge

26
Q

Are ionic compounds soluble in water?

A

Yes
Water molecules break the lattice and surround the ions

27
Q

What is simple covalent bonding?

A

Strong covalent bonds between atoms and weak VDW between molecules

28
Q

Are there any lone pair in simple covalent bonding?

A

No - they are all bonded

29
Q

Can simple covalent molecules conduct electricity?

A

No - no free electron

30
Q

So simple covalent molecules have a high/ low bp and mp?

A

Low - small amount of energy is needed to break the weak VDW between molecules

31
Q

Example of molecular covalent substances

A

Crystalline: Water (ice), iodine
Chlorine, oxygen

32
Q

Macromolecules

A

-high mp and bp: breaking lots of strong covalent bond
- don’t conduct electricity (except graphite)

33
Q

Example of macromolecules

A

Diamond, Graphite

34
Q

Properties of diamond

A

Hard- each C atom is bonded with 4 others (strong covalent bond)
High mp
Tetrahedral 109.5
Can’t conduct electricity

35
Q

Properties of graphite

A

Each C atom is bonded with 3 others
VDW between Layers - slide over
High mp
Hexagonal 120
Conduct electricity - delocalised electron

36
Q

Coordinate bond

A

Share two electrons from the same atom

37
Q

Example of coordinate bond

A

NH4+ , H3O+, BF4-

38
Q

Electronegativity

A

The ability to attract an electron in a covalent bond

39
Q

Electronegativity ______ across the period

A

Increases - the atomic radius decreases, so stronger attraction between the nucleus and electrons

40
Q

Electronegativity _____ decreases down the group

A

Decreases - the atomic radius increases as there are more shielding, so the attraction between the nucleus and the electrons in the covalent bond decreases

41
Q

Example of non - polar covalent bond

A

Cl-Cl
H-H
C-H

42
Q

Example of polar covalent bond

A

H-Cl
C-Cl
Be-Cl

43
Q

Why B-F is polar but BF3 is non - polar?

A

Because the shape is trigonal planar (symmetrical) , the polarities of the bond cancel each other out

44
Q

What other shape is non polar?

A

Linear, tetrahedral, octahedral

45
Q

Induced dipole - dipole forces
(VDW)

A

Larger atoms
More electrons
Greater VDW between atoms

46
Q

Permanent d-d forces

A

Polar molecules
Stronger than VDW

47
Q

Hydrogen bond

A

H atom and the lone pair of O/N/F
Strongest intermolecular forces

48
Q

Hess’s law

A

The enthalpy change for a chemical reaction is independent of the route taken

49
Q

Mean bond enthalpy

A

The measure of energy required to break one mole of a covalent bond In the gaseous state

AQA AS Chemistry (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions