Brainscape's Knowledge GenomeTM

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


See full index

AECHE > unit 1 - FOCUS > Flashcards

unit 1 - FOCUS Flashcards

content i need to REVISE (weaknesses)

1
Q

oxalate

A

C2O4 -

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

atomic absorption spectra

A

element-specific frequencies of electromagnetic radiation at which energy is absorbed when transitioning up from a ground to excited state, represented as a continuous spectrum of light with specific frequencies of light missing (black lines = gaps between energy levels, absorbed by the atom)

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

atomic emission spectra

A

element-specific frequencies of electromagnetic radiation at which energy is emmited when transitioning down from an excited to ground state, represented as specific frequencies of light (coloured lines on a black background = gaps between energy levels, emitted by the atom)

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

purpose of monochromator

A

unabsorbed light is focued through a slit, entering a monochromator that separates into specific frequencies and distinguishes wavelengths of interest

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

water of crystallisation

A

water chemically bonded into a crystal structure of ionic salts (completely embedded as full H2O molecule between lattice gaps)

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

hydrous salts

A

contain water of crystallisation

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

quantum dots (what are the compounds)

A

ZnS, ZnSe, CdSe

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

quantum dots (functions)

A

emit size-dependent wavelengths of light (small = violet, large = red)
used as a biological tracer due to fluorescent microscopy/photometry

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

dispersion forces (how do they arise)

A

arise in all substances, since electrons are constantly moving, and thus not always symmetrically distributed, resulting in a very temporary/momentary, weak “instantaneous dipole”

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

factors that influence dispersion forces

A

surface area, mass, number of atoms

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

how does surface area influence dispersion forces

A

larger surface area => ability of increased proximity between molecules => stronger forces

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

how does mass influence dispersion forces

A

heavier (more protons) => more electrons => more chance/likelihood AND increased strength of an instantaneous dipole

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

how does number of atoms influence dispersion forces

A

increased proximity / concentration
more electrons => more chance/likelihood of instantaneous dipole

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

what are dipole-dipole forces

A

interactions between polar molecules with a partial charge, specifically electrostatic attraction (and repulsion) between physically aligned covalent molecules experiencing temporary, relatively weak, Dipole Moment

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

factors that influence dipole-dipole forces

A

molecular dipole, size, surface area

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

how does molecular dipole influence dipole-dipole forces

A

stronger individual dipole => stronger electrostatic attraction => stronger overall dipole-dipole force

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

how does size influence dipole-dipole forces

A

larger molecule => more electrons => more chance AND increased strength of dipole => stronger electrostatic attraction => stronger force

18
Q

how does surface area influence dipole-dipole forces

A

increased proximity => increased physical alignment => stronger electrostatic attraction (by inverse square law) => stronger forces

19
Q

factors that influence hydrogen bonding

A

atomic radius (inversely)

20
Q

how does atomic radius influence hydrogen bonding

A

smaller atomic radius => electrons confined to a smaller space => increased density => stronger, condensed partial charge => stronger polarity => stronger hydrogen bonding

21
Q

factors that overall impact intermolecular forces

A

atomic radius, mass, surface area, number of electrons, size, molecular dipole strength

22
Q

how do intermolecular forces influence MP / BP

A

stronger intermolecular forces => more energy required to overcome electrostatic attraction and intermolecular forces => increased kinetic energy needed => higher melting and boiling point temperatures

23
Q

vapour pressure

A

tendency of a substance to evaporate

24
Q

how do intermolecular forces influence vapour pressure

A

weaker intermolecular forces => lower boiling points => increased vapour pressure and increased volatility

25
Q

pure substance

A

substances made of one type of moelcule with a FIXED / CONSTANT / UNIFORM COMPOSITION, AS WELL AS WELL DEFINED, CONSTANT PHYSICAL AND CHEMICAL PROPERTIES

26
Q

surface tension

A

measure of forces required to strecth or break the surface of a liquid, due to strong cohesive forces (hydrogen bonds)

27
Q

dissociation

A

ionic substance dissolving into separate, independent mobile ions

28
Q

ionisation

A

molecule splitting into individual ions, i.e. formation of charges

29
Q

ion-dipole forces

A

attraction between fully-charged ion and partically-charged dipole, occuring in all forms of dissolution between formed ions and water

30
Q

relationship between solubility of solids and temperature

A

more kinetic energy => particles able to move more => weakened intermolecular forces => can be overcome with less additional energy => dissociates and ionises more

31
Q

relationship between solubility of gases and temperature

A

more kinetic energy => particles able to move more => weakened intermolecular forces => more difficult to be “held” by solvent => “escapes” the surface of the solvent

32
Q

types of water pollution

A

sweage, disease causing aagents, sediment pollution, inorganic plant and algal nutrients, organic compounds, inorganic compounds, radioactive substances, thermal pollution

33
Q

factors of intermolecular forces that influence chromatography

A

types and charges of polar groups, molecular weight, molecular geometry

34
Q

how does the type and charge of polar groups influence chromatography

A

molecules preferentially bond with phase having the most similar bonding TYPE (thus the amount of same polar groups as well)

35
Q

how does molecular weight influence chromatography

A

heavier => larger => more likely to bond with stationary phase and remain in it longer => reduced Rf and increased Rt

36
Q

how does molecular geometry influence chromatography

A

greater surface area => more likely to bond with stationary phase and remain in it longer => reduced Rf and increased Rt

37
Q

normal phase

A

stationary POLAR, mobile NONPOLAR

38
Q

reverse phase

A

stationary NONPOLAR, mobile POLAR

39
Q

mobile phase in PC

A

solvent (water) progressing along the stationary phase (filter paper) due to capillary action (combination of cohesion and adhesion)

40
Q

advantages of TLC over PC

A

glass plate is more rigid than flexible paper; easier to control
after separation, substances can easily be recovered

AECHE (8 decks)

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