Chemistry A-Level
Sign conventions for enthalpy terms
What Sign conventions for enthalpy terms means in Chemistry A-Level, as defined for OCR.
Definition of Sign conventions for enthalpy terms
Check what you remember
Read the wording for your board, then hide it and explain Sign conventions for enthalpy terms in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
Lattice enthalpy and electron affinity are treated as exothermic, while ionisation and atomisation are treated as endothermic, with the correct sign applied to each step before summing.
Topics that use Sign conventions for enthalpy terms
- Lattice enthalpy (OCR A-Level)
Related terms
- Born–Haber cycle
- Effect of ionic charge and radius on lattice enthalpy
- Electron affinity
- Enthalpy change of hydration
- Enthalpy change of solution
- Enthalpy of atomisation
- enthalpy of formation
- Enthalpy sign and exothermic formation
Using Sign conventions for enthalpy terms in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Chemistry questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
Start free
All Chemistry A-Level termsA week of Premium from your first lesson · Then the free plan continues · No card, no charge