AQA A LEVEL Chemistry
Relative atomic mass - ANS -The average mass of an atom of an element, relative to 1/12th of
the mass of an atom of Carbon-12
Relative molecular mass - ANS -Average mass of a molecule compared to 1/12th of the mass
of a carbon-12 atom
The Avogradro constant - ANS -the number of particles in a mole
ideal gas equation - ANS -pV = nRT
empirical formula - ANS -the simplest whole number ratio of atoms of each element in a
compound
percentage atom economy - ANS -(Mass of desired product/total mass of reactants) x 100
ionic bonding - ANS -the electrostatic attraction between oppositely charged ions in a lattice
covalent bond - ANS -a shared pair of electrons between non-metal elements
coordinate bond - ANS -a shared pair of electrons where both electrons are supplied by one
atom
repulsion in shapes of molecules - ANS -Lone pair-lone pair > lone pair-bonding pair > bonding
pair-bonding pair
electronegativity - ANS -the power of an atom to attract the pair of electrons in a covalent bond
hess' law - ANS -Total enthalpy change for a reaction is independent of the route chosen
mean bond enthalpy - ANS -The energy required to break a covalent bond into gaseous atoms
averaged over different molecules
Bonds broken - bonds made
activation energy - ANS -The minimum amount of energy needed to start a chemical reaction
catalyst - ANS -A substance that increases the rate of a chemical reaction without being
changed by providing an alternative reaction pathway by lowering activation energy
, Le Chatelier's principle - ANS -When a system in dynamic equilibrium is subjected to change,
the position of equilibrium will shift to oppose the change.
oxidising agents - ANS -electron acceptors
reducing agents - ANS -electron donors
Enthalpy of formation - ANS -Enthalpy change when one mole of a compound is formed from
its constituent elements under standard conditions in their standard states
Enthalpy of atomization - ANS -The energy required to produce one mole of gaseous atoms
from an element in its standard state
Electron affinity - ANS -the enthalpy change when one mole of gaseous atoms forms one mole
of -1 ions
Lattice enthalpy of formation - ANS -Enthalpy change when one mole of a solid ionic compound
is formed from its constituent ions in the gas phase
Lattice enthalpy of dissociation - ANS -Energy change when 1 mol of an ionic lattice dissociates
to its gaseous ions.
standard electrode potential - ANS -298K
100kPa
1.00mol dm-3
Electrode reactions in lithium cell
(positive electrode) - ANS -Li+ + CoO2 + e- → Li+[CoO2]-
Electrode reactions in lithium cell
(negative electrode) - ANS -Li → Li+ + e-
Electrode reactions in hydrogen-oxygen fuel cell in acidic conditions
(positive electrode) - ANS -02 + 4H+ +4e- -> 2H20
Electrode reactions in hydrogen-oxygen fuel cell in acidic conditions
(negative electrode) - ANS -H2 -> 2H+ + 2e-
Brosted- lowry Acid - ANS -proton donor
Brosted- lowry base - ANS -proton acceptor
weak acids - ANS -partially dissociate in aqueous solution
Relative atomic mass - ANS -The average mass of an atom of an element, relative to 1/12th of
the mass of an atom of Carbon-12
Relative molecular mass - ANS -Average mass of a molecule compared to 1/12th of the mass
of a carbon-12 atom
The Avogradro constant - ANS -the number of particles in a mole
ideal gas equation - ANS -pV = nRT
empirical formula - ANS -the simplest whole number ratio of atoms of each element in a
compound
percentage atom economy - ANS -(Mass of desired product/total mass of reactants) x 100
ionic bonding - ANS -the electrostatic attraction between oppositely charged ions in a lattice
covalent bond - ANS -a shared pair of electrons between non-metal elements
coordinate bond - ANS -a shared pair of electrons where both electrons are supplied by one
atom
repulsion in shapes of molecules - ANS -Lone pair-lone pair > lone pair-bonding pair > bonding
pair-bonding pair
electronegativity - ANS -the power of an atom to attract the pair of electrons in a covalent bond
hess' law - ANS -Total enthalpy change for a reaction is independent of the route chosen
mean bond enthalpy - ANS -The energy required to break a covalent bond into gaseous atoms
averaged over different molecules
Bonds broken - bonds made
activation energy - ANS -The minimum amount of energy needed to start a chemical reaction
catalyst - ANS -A substance that increases the rate of a chemical reaction without being
changed by providing an alternative reaction pathway by lowering activation energy
, Le Chatelier's principle - ANS -When a system in dynamic equilibrium is subjected to change,
the position of equilibrium will shift to oppose the change.
oxidising agents - ANS -electron acceptors
reducing agents - ANS -electron donors
Enthalpy of formation - ANS -Enthalpy change when one mole of a compound is formed from
its constituent elements under standard conditions in their standard states
Enthalpy of atomization - ANS -The energy required to produce one mole of gaseous atoms
from an element in its standard state
Electron affinity - ANS -the enthalpy change when one mole of gaseous atoms forms one mole
of -1 ions
Lattice enthalpy of formation - ANS -Enthalpy change when one mole of a solid ionic compound
is formed from its constituent ions in the gas phase
Lattice enthalpy of dissociation - ANS -Energy change when 1 mol of an ionic lattice dissociates
to its gaseous ions.
standard electrode potential - ANS -298K
100kPa
1.00mol dm-3
Electrode reactions in lithium cell
(positive electrode) - ANS -Li+ + CoO2 + e- → Li+[CoO2]-
Electrode reactions in lithium cell
(negative electrode) - ANS -Li → Li+ + e-
Electrode reactions in hydrogen-oxygen fuel cell in acidic conditions
(positive electrode) - ANS -02 + 4H+ +4e- -> 2H20
Electrode reactions in hydrogen-oxygen fuel cell in acidic conditions
(negative electrode) - ANS -H2 -> 2H+ + 2e-
Brosted- lowry Acid - ANS -proton donor
Brosted- lowry base - ANS -proton acceptor
weak acids - ANS -partially dissociate in aqueous solution
