Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CHEMISTRY KEY WORDS > DEFINITIONS > Flashcards

DEFINITIONS Flashcards

1
Q

systematic errors

A

the same every time you repeat the experiment

  • caused by set up or equipment used
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

random errors

A

vary –> make big differnee each time you repeat exeriment

  • e.g. reading burette (when between 2 lines = above/below)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

% error

A

(uncertainty / reading) x 100

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

mass number (of element)

A

TOTAL number of protons + neutrons (in nucleus)

  • largest + top no.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

atomic/proton number

A

number of protons in element

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

isotope of an element

A

atoms with the same atomic number but DIFFERENT MASS NUMBER

= different no. of neutrons

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

J Thomson atom theory

A
  • pudding model

- corpuscles

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

Geiger-Marsden Experiment

A
  • fire ALPHA particles at thin sheet of GOLD
  • most passed through, few deflected backwards

Rutherford = nuclear model

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

Bohr Model

A
  • electrons in FIXED ORBITALS
  • each shell = FIXED ENERGY
  • when electron moves between shells, EMR emitted/absorbed
  • radiation = FIXED FREQUENCY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

relative atomic mass, Ar

A

the avg. mass of an atom of an element on a scale when an atom of carbon-12 is 12

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

Avogadros constant

A

no. of particles in 1 mole = 6.02 x 10^23

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

% yield

A

(actual / theoretical) x 100

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

ionic bonding

A

chemical bond formed between 2 ions with opposite charges

- electrostatic attraction

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

covalent bonding

A

2 atoms share electrons so they both have full outer shells of electrons
- both the + nuclei are attracted to the shared electrons

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

dative covalent bond

A

one atoms donates both electrons to a bond

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

first ionisation enthalpy

A

energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions

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

thermal decomposition

A

when a substance breaks down when it’s heated

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

salt

A

when the H+ atom in an acid replaced by a (metal/ammonium/positive) ion

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

Electromagnetic spectrum

A 
Rotten
Men
Inevitabily
Visit
Ugly 
X
Girlfriends
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Planck’s constant

A

6.63 x 10^-34

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

nuclear fusion

A

2 small nuclei combine under high temp. + pressure –> one larger nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

enthalpy change

A

the energy transferred in a reaction at constant pressure (kj mol-1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

standard enthalpy change of REACTION

A

EC when the reaction occurs in MOLAR quantities shown in the chemical equation under SC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

standard enthalpy change of FORMATION

A

EC when 1 MOLE of a COMPOUND is formed from its ELEMENTS in their standard states under SC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
standard enthalpy change of COMBUSTION
EC when 1 MOLE of a substance iss completely BURNED IN OXYGEN under SC
26
calorimetry
find how much heat is given out by a reaction by measuring the temperature change o some water
27
standard enthalpy change of NEUTRALISATION
EC when an ACID + ALKALI react together under SC to form 1 MOLE H2O
28
exothermic reaction
RELEASES energy - negative
29
endothermic reaction
ABSORBS energy - positive +
30
average bond enthalpy
the energy needed to break 1 MOLE of bonds in the GAS PHASE AVERAGED over many DIFFERENT COMPOUNDS
31
catalyst
increase RR by providing an alternative reaction pathway with a LOWER A.E - its chemically unchanged at the end of reaction
32
haber process
- makes ammonia - iron Fe catalyst N2(g) + 3H2(g) 2NH3(g)
33
cracking
long chain hydrocarbons broken into smaller hydrocarbons - alkENE and alkANE - products = random
34
heterogeneous catalyst
DIFFERENT physical state to reactants
35
catalytic converter
platinum heterogeneous catalyst | change pollutants into harmless gases
36
what happens to pollutants in the atmosphere (ozone)
light shines on oxides of nitrogen & unburnt hydrocarbons --> low level OZONE produced not good + can combine with other pollutants to form smog = smog - cough + choke
37
how does a heterogeneous catalyst work?
- reactant mol. ADSORBED onto catalyst surface - bonds between reactant = weakened and break up = radicals - bonds form (radicals join) = new molecules / product - product DESORBS from surface
38
arenes / aromatic compound
benzene ring
39
aliphatic compound
no benzene ring
40
hydroxyl group
-OH alcohol group
41
double bond (whats it made of)
sigma + pi bond
42
pi bond
two p-orbitals overlap sideways
43
structural isomer
same molecular formula | different structural formula
44
stereoisomers
same shortened formula | different arrangement in space
45
cis/trans isomerism
when theres not 2 H's
46
addition polymerisation
double bond in alkenes open + join together to make long chains called polymers
47
biofuel
fuels made from LIVING MATTER over a SHORT period of time
48
fuel cell
coverts H2 + O2 into H2O - WATER
49
electrolysis
passing an ELECTRIC current through an IONIC substance that's MOLTEN or in SOLUTION = breaks down into the ELEMENTS it's made of
50
anode
+ positive electrode A+
51
cathode
- negative electrode C-
52
brine
solution of water with a HIGH CONC. of SALTS
53
reduction
GAIN electrons
54
oxidation
LOSS of electrons
55
oxidising agent
reduced
56
reducing agent
oxidised
57
redox reaction
when reduction and oxidation happen simultaneously
58
halogens
group 7 - highly reactive
59
hydrogen halide
halogen + hydrogen e.g. HCl
60
dynamic equilibrium
- forward = SAME RATE as backward reaction | * occurs in a CLOSED system
61
Kc
equilibrium constant * only true for particular TEMP Kc > 1 = right
62
electronegativity
the ability of an atom to attact the bonding electrons in a COVALENT bond
63
Pauling Scale
measures electronegativity | F = highest
64
dipole
a difference in charge between 2 atoms caused by a SHIFT in ELECTRON DENSITY in the bond
65
polar molecule
has a overall dipole caused by the presence of a permanent charge across the mol.
66
instantaneous dipole - induced dipole bonds
cause ALL atoms to be ATTRACTED to each other - elctrons in charge cloud = always moving = temp dipole - induces another in OPPOSITE direction on neighbouring atom - 2 dipole = attracted - induces another - domino effect - created + destroyed constantly - overall effect = attracted to each other
67
permanent dipole - permanent dipole
δ+ and δ- charges on POLAR mol. = | weak ELECTROSTATIC forces of attraction between mol.
68
hydrogen bonding
hydrogen COVALENTLY bonded to F O N * FON = very electronegative - bond = polarised + H has high charge density ---> weak bonds with LONE PAIRS of electrons e.g. water + ammonia
69
Boltzmann distribution curve
graph showing: - number of molecules vs KINETIC energy - AE is shown towards right of graph
70
homogeneous catalysts
same states as reactants - form INTERMEDIATE compounds - provides alternative reaction pathway with lower AE
71
haloalkane
ALKANES with HALOGEN atoms
72
nucleophile
electron-pair DONOR * negative e. g. OH-, NH3, H2O
73
nucleophilic substitution reaction
a nucleophile attacks a δ+ C and replaces the δ- atom/group | a functional group replaced
74
amines
ammonia but 1 or more H's replaced by ALKYL group
75
heterolytic fission
2 DIFFERENT substances formed | - +cation (X+) and -negative anion (Y-)
76
homolytic fission
2 electrically uncharged RADICALS formed
77
radicals
particles with unpaired electron
78
CFC
chlorofluorocarbons
79
parts per million
% x 10,000
80
E = h v
energy (j) = planck's constant (6.63 x 10^-34) x frequency (Hz)
81
reflux
- dont lose any VOLATILE organic substances | - heat in round bottomed flask fitted with LIEBIG condenser
82
distillation
- separates substances with different boiling points
83
separation
removes any water soluble inpurities from product - organic layer is less dense than aqueous layer (where impurities dissolve) so floats on top
84
drying a substance
+ anhydrous salt = drying agent e.g. MgSO4, CaCl2 it binds to water to become hydrated
85
filtration
isolate SOLID organic product * BUCHNER funnel
86
recrystallisation
PURIFYING organic solid products
87
thin layer chromatography
simple way of separating mixtures - mobile (solvent)+ stationary (silica/alumina) phase - solvent front - result = chromatogram * fluorescent dye + UV light OR iodine vapour
88
Rf
distance travelled by SPOT / distance travelled by SOLVENT
89
green chemistry principles
- renewable resources - all chemicals amd processes = safe as possible - waste minimised + products biodegradable/recyclable
90
rate of reaction
change in the amount of reactants / producst per unit of time (usually s)
91
rate equation
general reaction : A + B --> C + D rate = k[A]m[B]n
92
intitial rate (equation)
amount reactant used or product formed / TIME
93
half-life
TIME taken for a reactant to HALVE in quantity
94
rate-determining step
SLOWEST step in a multi-step reaction
95
amino acids
AMINO group + CARBOXYL group
96
zwitterion
- overall NEUTRAL mol. - has + and - charge in different parts of mol. * only occurs near its isoelectric point
97
isoelectric point
the pH where the OVERALL CHARGE on amino acid is 0
98
paper chromatography
used to identify unknow AMINO ACIDS *ninhydrin solution (purple)/ iodine crystals (brown)
99
proteins
CONDENSATION polymers* made by joining together lots of AA MONOMERS with PEPTIDE links *(amine + COOH group react)
100
primary structure
SEQUENCE of AA in the POLYPEPTIDE chain
101
secondary structure
- peptide links form HYDROGEN bonds - alpha-helix (spiral) - beta-pleated sheet
102
tertiary structure
EXTRA BONDS form between different parts of the polypeptide chain - gives the protein 3D SHAPE - ID - ID = 2 non-polar side groups - ionic interactions = charged side groups - H bonds - disulfide bridge = (cysteine) thiol groups (-SH)
103
DNA
polymer of NUCLEOTIDES - phosphate group - pentose sugar - base attached to sugar-phosphate backbone
104
RNA
same as DNA but... - ribose sugar - URACIL not thymine
105
condensation polymerisation
forms sugar phosphate backbone in DNA and RNA - phosphate + sugar react = H2O lost + PHOSPHATE-ESTER link
106
gene
each protein is CODED for by a separate section of DNA called a gene - genes contain info about the correct order of AA
107
condensation polymerisation
forms sugar phosphate backbone in DNA and RNA - phosphate + sugar react = H2O lost + PHOSPHATE-ESTER link
108
gene
each protein is CODED for by a separate section of DNA called a gene - genes contain info about the correct order of AA

CHEMISTRY KEY WORDS (1 decks)

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