AQA A LEVEL Chemistry questions and
answers
Relative atomic mass - 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 - Average mass of a molecule compared to 1/12th of the
mass of a carbon-12 atom
The Avogradro constant - the number of particles in a mole
ideal gas equation - pV = nRT
empirical formula - the simplest whole number ratio of atoms of each element in
a compound
percentage atom economy - (Mass of desired product/total mass of reactants) x
100
ionic bonding - the electrostatic attraction between oppositely charged ions in a
lattice
,AQA A LEVEL Chemistry questions and
answers
covalent bond - a shared pair of electrons between non-metal elements
co-ordinate bond - a shared pair of electrons where both electrons are supplied by
one atom
repulsion in shapes of molecules - Lone pair-lone pair > lone pair-bonding pair >
bonding pair-bonding pair
electronegativity - the power of an atom to attract the pair of electrons in a
covalent bond
hess' law - Total enthalpy change for a reaction is independent of the route
chosen
mean bond enthalpy - The energy required to break a covalent bond into gaseous
atoms averaged over different molecules
Bonds broken - bonds made
, AQA A LEVEL Chemistry questions and
answers
activation energy - The minimum amount of energy needed to start a chemical
reaction
catalyst - 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 - When a system in dynamic equilibrium is subjected to
change, the position of equilibrium will shift to oppose the change.
oxidising agents - electron acceptors
reducing agents - electron donors
Enthalpy of formation - Enthalpy change when one mole of a compound is formed
from its constituent elements under standard conditions in their standard states
Enthalpy of atomization - The energy required to produce one mole of gaseous
atoms from an element in its standard state
answers
Relative atomic mass - 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 - Average mass of a molecule compared to 1/12th of the
mass of a carbon-12 atom
The Avogradro constant - the number of particles in a mole
ideal gas equation - pV = nRT
empirical formula - the simplest whole number ratio of atoms of each element in
a compound
percentage atom economy - (Mass of desired product/total mass of reactants) x
100
ionic bonding - the electrostatic attraction between oppositely charged ions in a
lattice
,AQA A LEVEL Chemistry questions and
answers
covalent bond - a shared pair of electrons between non-metal elements
co-ordinate bond - a shared pair of electrons where both electrons are supplied by
one atom
repulsion in shapes of molecules - Lone pair-lone pair > lone pair-bonding pair >
bonding pair-bonding pair
electronegativity - the power of an atom to attract the pair of electrons in a
covalent bond
hess' law - Total enthalpy change for a reaction is independent of the route
chosen
mean bond enthalpy - The energy required to break a covalent bond into gaseous
atoms averaged over different molecules
Bonds broken - bonds made
, AQA A LEVEL Chemistry questions and
answers
activation energy - The minimum amount of energy needed to start a chemical
reaction
catalyst - 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 - When a system in dynamic equilibrium is subjected to
change, the position of equilibrium will shift to oppose the change.
oxidising agents - electron acceptors
reducing agents - electron donors
Enthalpy of formation - Enthalpy change when one mole of a compound is formed
from its constituent elements under standard conditions in their standard states
Enthalpy of atomization - The energy required to produce one mole of gaseous
atoms from an element in its standard state
