chemtistry definitions post mocks
0.0 / 5
- Created by: charlie
- Created on: 19-04-14 15:14
heterolytic fission
breaking of covalent bond with both of the bonded electrons going to one of the atoms (cation + anion_
1 of 39
activation energy
minimum energy required to start a reaction without breaking bonds
2 of 39
addition polymerisation
process in which unsaturated alkene molecules add onto growing polymer chain to form very long saturated molecular chain (addition polymer)
3 of 39
addition reaction
reactant added to unsaturated molecule to make saturated molecule
4 of 39
atom economy
EQUATION...
5 of 39
atomic orbital
region within an atom that can hold up to two electrons with opposite spins
6 of 39
average bond enthalpy
average enthalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in molecules of gaseous species
7 of 39
bond enthalpy
enthalpy change that takes place when breaking by homolytic fission 1 mol of given bond in molecules of gaseous species
8 of 39
carbocation
organic ion which a carbon atom has negative charge
9 of 39
catalyst
substance that increases the rate of chemical reaction without being used up in the process
10 of 39
cracking
breaking down of long-chained saturated hydrocarbons to form mixture of shorter chained alkanes + alkenes
11 of 39
delocalised electron
electrons shared between more than 2 atoms
12 of 39
displacement reaction
reaction which more reactive element displaces a less reactive element from an aqueous solution of the latter's ions
13 of 39
dynamic equilibrium
equilibrium that exists in a closed system when the rate of the forward reaction is equal to the reverse reaction
14 of 39
E/Z isomerism
type of stereoisomerism which different groups attached to each carbon of C=C bond may be arranged differently in space due to restricted rotation of C=C bond
15 of 39
electron shielding
repulsion between electrons in different inner shells reducing net attraction from +ve nucleus on outer electron
16 of 39
electrophile
atom(s) attracted to electron-rich centre or atom where it accepts a pair of electrons to form a new covalent bond
17 of 39
endothermic reaction
reaction where enthalpy of product > enthalpy of reactants (results in heat being taken from surroundings)
18 of 39
(standard) enthalpy change of reaction
enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions reactants and products in standard states
19 of 39
exothermic
enthalpy of product < enthalpy of reactants (heat loss to surroundings)
20 of 39
fractional distillation
separation of components in a liquid mixture into fractions which differ in boiling points
21 of 39
fragmentation
process in mass spectrometry that causes +ve ion to spilt into pieces (one of which is +ve fragment ion)
22 of 39
giant covalent / ionic / metallic lattice
3-d structure of atoms bonded by strong covalent bonds / of opposite charge ions bonded by strong ionic bonds / of +ve ions and delocalised electrons bonded by strong metallic bonds
23 of 39
greenhouse effect
absorbtion + subsequent emission of infrared radiation by atmospheric gases warms the lower atmosphere + planet surface
24 of 39
heterogeneous catalysis
catalyst has a different physical state from reactants; frequently reactants are gases + catalysts solid
25 of 39
homogenous catalysis
catalyst + reactants in same physical state (most frequently gaseous or aqueous)
26 of 39
homolytic fission
breaking of covalent bond with one of bonded electrons going to each atoms (forms radicals)
27 of 39
(successive) ionisation energy
measure of energy required to remove each electron in turn
28 of 39
le Chatelier's principle
when a system is in dynamic equilibrium its subject to change, position of equilibrium will shift to minimise the change
29 of 39
nucleophile
atom(s) attracted to electron-deficient centre or atom, where it donates a pair of electrons to form new covalent bond
30 of 39
nucleophilic substitution
substitution reaction in which nucleophile attracted to electron-deficient centre or atom, where it donates a pair of electrons to form new covalent bond
31 of 39
percentage yield
EQUATION...
32 of 39
radical
species with unpaired electron
33 of 39
rate of reaction
change in concentration of a reactant or product in a given time
34 of 39
salt
chemical compound formed from acid, when H + ion from the acid replaced by metal ion or +ve ion (e.g. NH4+)
35 of 39
shell
group of atomic orbitals with same principal quantum number (main energy level)
36 of 39
specific heat capacity
energy required to raise temperature of 1g of substance by 1
37 of 39
sub-shell
group of same type of atomic orbitals (S,P,D,F) within a shell
38 of 39
volatility
ease with which a liquid turns into a gas (volatility increases as boiling point decreases)
39 of 39
Other cards in this set
Card 2
Front
minimum energy required to start a reaction without breaking bonds
Back
activation energy
Card 3
Front
process in which unsaturated alkene molecules add onto growing polymer chain to form very long saturated molecular chain (addition polymer)
Back
Card 4
Front
reactant added to unsaturated molecule to make saturated molecule
Back
Card 5
Front
EQUATION...
Back
Related discussions on The Student Room
- protein a level biolgy AqA »
- shape of molecules a level chem »
- AQA Chem Unit 1 May 22nd 2015 *OFFICIAL THREAD* »
- Will the bond angle in H2O(104.5) increase if water is bind to other molecules? »
- a level chemistry aqa »
- Shapes of molecules »
- BSF polarity »
- Chemistry - melting point »
- A level chem dipole question help needed! »
- a level chemistry drawing moelceules »
Similar Chemistry resources:
0.0 / 5
0.0 / 5
3.0 / 5 based on 1 rating
0.0 / 5
2.5 / 5 based on 3 ratings
2.0 / 5 based on 1 rating
2.0 / 5 based on 1 rating
Comments
No comments have yet been made