Chemistry A-Level
Hess's law for indirect determination
What Hess's law for indirect determination means in Chemistry A-Level, as defined for OCR.
Definition of Hess's law for indirect determination
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Reference: OCR
Used when a reaction cannot be measured directly, for example combining enthalpy of combustion or formation data, or measuring a related reaction and reversing or scaling steps.
Topics that use Hess's law for indirect determination
- Enthalpy changes (OCR A-Level)
Related terms
- ∆H of combustion
- ∆H of formation
- Activation energy
- Approximate estimate
- Average bond enthalpy
- Averaging over gaseous compounds
- Bond breaking and bond making
- Bond enthalpy
Using Hess's law for indirect determination in the exam
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