Download AS Definitions

AS Definitions
Unit 1
1.1 Atomic Structure
mass number (A)
atomic (proton)
number (Z)
isotopes
ionisation energy
First ionisation energy
Relative atomic mass
(Ar)
relative isotopic mass
Relative formula mass
Relative molecular
mass (Mr)
1.2 Amount of
substance
relative atomic mass
(Ar)
relative molecular
mass (Mr)
relative formula mass
mole
ideal gas equation
Empirical formula
molecular formulae
% atom economy
1.3 Bonding
Covalent bond
Co-ordinate bond
Dative bond
Metallic bond
Electronegativity
ionic bonding
1.4 Periodicity
s block element
p block element
d block element
First ionisation energy
Total number of protons and neutrons in the nucleus of an atom
Number of protons in the nucleus of an atom
Atoms with the same number of the protons but different numbers of neutrons
The energy required to remove a mole of electrons from a mole of gaseous atoms
or ions
Enthalpy required to remove a mole of electrons from a mole of gaseous atoms to
form a mole of uni-positive ions
Weighted average mass of one mole of atoms
1
/12 mass of one mole of 12C atoms
mass of one mole of a specific isotope
1
/12 mass of one mole of 12C atoms
Ave mass of one mole of entities
1
/12 mass of one mole of 12C
Ave mass of one mole of molecules
1
/12 mass of one mole of 12C
Weighted average mass of one mole of atoms
1
/12 mass of one mole of 12C atoms
Ave mass of one mole of molecules
1
/12 mass of one mole of 12C
Ave mass of one mole of entities
1
/12 mass of one mole of 12C
Number of particles in exactly 12g of 12C
pV = nRT
simplest ratio of atoms of each element in compound
Actual number of atoms of each element in a compound
(mass of desired product / total mass of reactants) x100
The attraction between a shared pair of electrons and the nuclei held by the bond
Covalent bond in which both electrons come from one atom
See co-ordinate bond
Force of attraction between positive metal ions and negative delocalised electrons
held in a lattice
The power of an atom or nucleus to withdraw electron density towards itself in a
covalent bond
Strong multidirectional electrostatic forces of attraction between oppositely
charged ions
Element that has its highest energy electrons in an s-orbital
Element that has its highest energy electrons in an p-orbital
Element that has its highest energy electrons in an d-orbital
Enthalpy required to remove an electron from a gaseous atom to form a unipositive ion
1.5 Introduction to
Organic Chemistry
alkanes
alkenes
displayed formula
empirical formula
homologous series
Isomers
molecular formula
structural formula
structural isomers
haloalkanes
Structural isomerism
Chain isomerism
Positional isomerism
functional group
isomerism
Alkanes 1.6
Hydrocarbon
Alkane
Saturated
hydrocarbon
petroleum
Fraction
Fractional distillation
cracking
Saturated hydrocarbons with general formulae CnH2n+2
Unsaturated hydrocarbons with general formula CnH2n
Formula in which all the atoms and all the bonds are shown e.g. butan-1-ol is
The simplest whole number ratio in which the atoms in a compound combine
together
Family of organic compounds with the same functional group but different chain
length. They:
 have the same general formula
 have similar chemical properties
 show a trend in physical properties
 differ from the next member of the series by –CH2
Molecules with the same molecular formula but whose atoms are arranged
differently
 structural isomers: molecules with the same molecular formula but
different structural formulae
o positional isomers have the same functional group attached to the
main chain at different points
o functional group isomers have different functional groups
o chain isomers have a different arrangement of the hydrocarbon
chain, e.g. branching
 stereoisomerism – see Unit 2.15 Alkenes
The formula giving the numbers of atoms of each different element tin a molecule
of the compound e.g. butan-2-ol is C4H10O
Formula of an organic molecule in which bonds are not shown but each carbon
atom is written with the atoms (or groups) attached to it. E.g. butan-2-ol is
CH3CH2CH(OH)CH3
molecules with the same molecular formula but different structural formulae
Alkanes in which one or more hydrogen atom has been replaced with a halogen
atom
Molecules with the same molecular formula but different structural formulae
Molecules with the same molecular formula but a different arrangement of the
hydrocarbon chain e.g. branching [a form of structural isomerism]
Molecules with the same molecular formula but the functional group is attached
to the main chain at different positions [a form of structural isomerism]
Molecules with the same molecular formula but the functional groups are
different [a form of structural isomerism]
Compounds containing hydrogen and carbon only
Saturated hydrocarbons with general formulae CnH2n+2
Compound of only carbon and hydrogen containing only single bonds
Mixture of hydrocarbons
Mixture of hydrocarbons with similar boiling points
Separation of components because of differing boiling points
Breaking of C–C bonds in large alkanes to produce smaller alkanes and alkenes
Catalytic cracking
Thermal cracking
Complete combustion
Incomplete
combustion
Breaking of C–C bonds in large alkanes; catalytic cracking takes place at a slight
pressure, high temperature and in the presence of a zeolite catalyst and is used
mainly to produce motor fuels and aromatic hydrocarbons
Breaking of C–C bonds in large alkanes; thermal cracking takes place at high
pressure and high temperature and produces a high percentage of alkenes
Combustion in plentiful supply of oxygen in which all elements undergo complete
oxidation
Combustion in limited supply of oxygen
Unit 2
2.7 Energetics
enthalpy change (H)
Hess’s Law
mean bond enthalpy
standard conditions
standard enthalpy of
combustion (Hc )
standard enthalpy of
formation (Hf )
Standard enthalpy
change (Hθ)
2.8 Kinetics
activation energy
Catalyst
Homogeneous
catalyst
Heterogeneous
catalyst
Rate of reaction
the heat energy change measured under conditions of constant pressure
The enthalpy change for a reaction is independent of the route
enthalpy needed in breaking) covalent bond(s)
averaged for that type of bond over a range of molecules
100 kPa and a stated temperature (e.g. H298)
Enthalpy change when 1 mol of a substance
is completely burned in
at 298 K and 100 kPa (i.e. under standard conditions)
(Enthalpy change) when 1 mol of a compound is formed
from its constituent elements in their standard states
the heat energy change measured under standard conditions of 100 kPa and a
stated temperature (often 298K)
Minimum energy required for a reaction to occur
A substance that alters the rate of a reaction but is chemically unchanged at the
end
Catalyst that is in the same phase as the reactants
Catalyst that is in a different phase to the reactants
Measured change in concentration of a substance in unit time
2.9 Equilibria
Reversible reaction
Le Chatelier’s
Principle
enthalpy change (H)
Reaction in which both forward and back reactions occur at equal rates, with
concentrations of both reactants and products constant.
If a change is imposed on a system at equilibrium, the equilibrium will shift to
oppose the change
the heat energy change measured under conditions of constant pressure
2.10 Redox
Oxidation
Oxidising agent
Reduction
Reducing agent
oxidation is the process of electron loss
oxidising agents are electron acceptors
reduction is the process of electron gain
reducing agents are electron donors
2.11 Halogens
Electronegativity
The power of an atom or nucleus to withdraw or attract electrons or electron
Dynamic equilibrium
density or a pair of electrons (towards itself) in a covalent bond
2.12 Group 2
first ionisation energy
Enthalpy required to remove a mole of electrons from a mole of gaseous atoms to
form a mole of uni-positive ions
2.13 Metal extraction
2.14 Haloalkanes
Elimination
free-radical
Nucleophile
2.15 Alkenes
Addition
polymerisation
Alkene
Biodegradable
Electrophile
Geometrical isomers
(E-Z isomers)
Stereoisomerism
2.16 Alcohols
Biofuel
carbon neutral
Reaction in which an atom or group of atoms is removed from a reactant
Chemical species with an unpaired electron
Species with a lone pair of electrons that can be used to form a covalent bond
Reaction in which many alkene monomers join to form long chains as the only
product
Unsaturated hydrocarbon with general formula CnH2n
Can be broken down by microbes
Electron pair acceptor
A form of stereoisomerism that arises because of restricted rotation about the C=C
bond in alkenes
Compounds with the same structural formula with atoms (or bonds or groups)
arranged differently in space
Fuel produced from renewable biological sources
Reaction in which there is no net / overall (annual) carbon dioxide / CO2 emission
to the atmosphere
2.17 Analytical
techniques
molecular ion
Fingerprint region
Ion formed by the loss of one electron when a molecule is ionised in a mass
spectrometer
Area of an infra-red spectrum below about 1500 cm-1; caused by complex
vibrations of the whole molecule and characteristic of a particular molecule.