OCR A LEVEL CHEMISTRY EXAMINATION- 2026
ENTHALPY DEFINITIONS
(Physical Chemistry – Energetics)
Qualification: A Level Chemistry (OCR Specification A)
Paper Code: H432/01
Topic Area: Enthalpy & Energy Changes
Date: __________________________
Time: __________________________
Duration: ______________________
Total Marks: ___________________
INSTRUCTIONS TO CANDIDATES
Answer ALL questions.
Define each term precisely using correct scientific language.
Include “1 mole” and “standard conditions” where required.
Support definitions with equations or examples where appropriate.
Write clearly in black ink.
CANDIDATE DETAILS
, Full Name: ____________________________________________
Candidate Number: _____________________________________
Centre Number: ________________________________________
Signature: _________________________
Define standard enthalpy change of formation.
The enthalpy change when one mole of a substance is formed from its elements, with all
reactants and products in their standard states under standard conditions
Define standard enthalpy change of combustion.
The enthalpy change when one mole of a substance completely combusts, with all reactants
and products in their standard sates under standard conditions
Define the term enthalpy change of neutralisation and write the ionic equation for the this
change. Include state symbols.
The enthalpy change for the formation of 1 mole H₂O from the reaction of an acid with a base.
ENTHALPY DEFINITIONS
(Physical Chemistry – Energetics)
Qualification: A Level Chemistry (OCR Specification A)
Paper Code: H432/01
Topic Area: Enthalpy & Energy Changes
Date: __________________________
Time: __________________________
Duration: ______________________
Total Marks: ___________________
INSTRUCTIONS TO CANDIDATES
Answer ALL questions.
Define each term precisely using correct scientific language.
Include “1 mole” and “standard conditions” where required.
Support definitions with equations or examples where appropriate.
Write clearly in black ink.
CANDIDATE DETAILS
, Full Name: ____________________________________________
Candidate Number: _____________________________________
Centre Number: ________________________________________
Signature: _________________________
Define standard enthalpy change of formation.
The enthalpy change when one mole of a substance is formed from its elements, with all
reactants and products in their standard states under standard conditions
Define standard enthalpy change of combustion.
The enthalpy change when one mole of a substance completely combusts, with all reactants
and products in their standard sates under standard conditions
Define the term enthalpy change of neutralisation and write the ionic equation for the this
change. Include state symbols.
The enthalpy change for the formation of 1 mole H₂O from the reaction of an acid with a base.
