AQA A LEVEL Chemistry / Study Guide Questions &
Answers 2025-2026.
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
Practice questions for this set
Learn / Study with Learn
the electrostatic attraction between oppositely charged ions in a lattice
Choose matching term
1 Lattice enthalpy of formation 2 ionic bonding
3 condensation polymers 4 hess' law
Don't know?
Terms in this set (119)
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
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 Lone pair-lone pair > lone pair-bonding pair > bonding pair-
molecules 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
activation energy The minimum amount of energy needed to start a chemical
reaction
A substance that increases the rate of a chemical reaction
catalyst 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
Answers 2025-2026.
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
Practice questions for this set
Learn / Study with Learn
the electrostatic attraction between oppositely charged ions in a lattice
Choose matching term
1 Lattice enthalpy of formation 2 ionic bonding
3 condensation polymers 4 hess' law
Don't know?
Terms in this set (119)
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
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 Lone pair-lone pair > lone pair-bonding pair > bonding pair-
molecules 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
activation energy The minimum amount of energy needed to start a chemical
reaction
A substance that increases the rate of a chemical reaction
catalyst 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
