AQA A LEVEL CHEMISTRY PAPER 2 (2025) EXAM
QUESTIONS AND ALL CORRECT ANSWERS 100% SOLVED
AND GUARANTEED SUCCESS!! Questions And Answers
2025/2026
Relative atomic mass (Ar) - CORRECT ANSWER-Average mass of an atom
compared with one twelth of the mass of an atom of carbon 12
Electronegativity - CORRECT ANSWER-Power of an atom to attract the pair of
electrons in a covalent bond
Standard enthalpy of combustion - CORRECT ANSWER-Enthalpy change when 1
mole of a substance burns completely in oxygen under standard conditions with
all reactants and products being in their standard state
Standard enthalpy of formation - CORRECT ANSWER-Enthalpy change when 1
mole of a compound is formed from it's elements under standard conditions in
their standard states
Mean bond enthalpy - CORRECT ANSWER-The average energy needed to break a
certain type of bond over a range of compounds
Activation energy - CORRECT ANSWER-Minimum energy required for colliding
molecules to react
,Maxwell-Boltzmann distribution x and y axes - CORRECT ANSWER-x: Energy
y: fraction/number of molecules
What happens to the Maxwell-Boltzmann curve when temperature increases -
CORRECT ANSWER-Moves down and to the right
Rate of reaction - CORRECT ANSWER-Rate at which product formed/reactant used
up
Order of reaction - CORRECT ANSWER-Power to which the concentration of a
species is raised in the rate equation
rearrange k=Ae^-Ea/Rt - CORRECT ANSWER-lnk=-Ea/Rt+lnA
Conditions for thermal cracking - CORRECT ANSWER-High temperature and high
pressure
Products of thermal cracking - CORRECT ANSWER-High % of alkenes
Conditions for catalytic cracking - CORRECT ANSWER-High temperature ,slight
pressure and in the presence of a zeolite catalyst
, Products of catalytic cracking - CORRECT ANSWER-Motor fuels and aromatic
hydrocarbons
Why do we crack alkanes? - CORRECT ANSWER-Smaller alkanes/alkenes generally
more useful than longer chain ones
Equation for complete combustion of alkanes - CORRECT ANSWER-alkane +
oxygen > carbon dioxide + water
Equations for incomplete combustion of alkanes - CORRECT ANSWER-alkane +
oxygen > carbon monoxide/carbon + water
Pollutants produced by combustion engines - CORRECT ANSWER-NOx, CO, C and
sunburned hydrocarbons
Reaction of methane with chlorine - CORRECT ANSWER-I: Cl2 > 2Cl•
P: CH4 + Cl• > CH3• + Chi
CH3• + Cl2 > CH3Cl + Cl•
T: CH3• + Cl• > CH3Cl
2 equations showing decomposition of the ozone - CORRECT ANSWER-Cl• + O3 >
ClO• + O2
ClO• + O3 > 2O2 + Cl•
QUESTIONS AND ALL CORRECT ANSWERS 100% SOLVED
AND GUARANTEED SUCCESS!! Questions And Answers
2025/2026
Relative atomic mass (Ar) - CORRECT ANSWER-Average mass of an atom
compared with one twelth of the mass of an atom of carbon 12
Electronegativity - CORRECT ANSWER-Power of an atom to attract the pair of
electrons in a covalent bond
Standard enthalpy of combustion - CORRECT ANSWER-Enthalpy change when 1
mole of a substance burns completely in oxygen under standard conditions with
all reactants and products being in their standard state
Standard enthalpy of formation - CORRECT ANSWER-Enthalpy change when 1
mole of a compound is formed from it's elements under standard conditions in
their standard states
Mean bond enthalpy - CORRECT ANSWER-The average energy needed to break a
certain type of bond over a range of compounds
Activation energy - CORRECT ANSWER-Minimum energy required for colliding
molecules to react
,Maxwell-Boltzmann distribution x and y axes - CORRECT ANSWER-x: Energy
y: fraction/number of molecules
What happens to the Maxwell-Boltzmann curve when temperature increases -
CORRECT ANSWER-Moves down and to the right
Rate of reaction - CORRECT ANSWER-Rate at which product formed/reactant used
up
Order of reaction - CORRECT ANSWER-Power to which the concentration of a
species is raised in the rate equation
rearrange k=Ae^-Ea/Rt - CORRECT ANSWER-lnk=-Ea/Rt+lnA
Conditions for thermal cracking - CORRECT ANSWER-High temperature and high
pressure
Products of thermal cracking - CORRECT ANSWER-High % of alkenes
Conditions for catalytic cracking - CORRECT ANSWER-High temperature ,slight
pressure and in the presence of a zeolite catalyst
, Products of catalytic cracking - CORRECT ANSWER-Motor fuels and aromatic
hydrocarbons
Why do we crack alkanes? - CORRECT ANSWER-Smaller alkanes/alkenes generally
more useful than longer chain ones
Equation for complete combustion of alkanes - CORRECT ANSWER-alkane +
oxygen > carbon dioxide + water
Equations for incomplete combustion of alkanes - CORRECT ANSWER-alkane +
oxygen > carbon monoxide/carbon + water
Pollutants produced by combustion engines - CORRECT ANSWER-NOx, CO, C and
sunburned hydrocarbons
Reaction of methane with chlorine - CORRECT ANSWER-I: Cl2 > 2Cl•
P: CH4 + Cl• > CH3• + Chi
CH3• + Cl2 > CH3Cl + Cl•
T: CH3• + Cl• > CH3Cl
2 equations showing decomposition of the ozone - CORRECT ANSWER-Cl• + O3 >
ClO• + O2
ClO• + O3 > 2O2 + Cl•
