Activation energy
What Activation energy means in Chemistry A-Level, as defined for AQA, OCR.
Definitions of Activation energy
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Reference: OCR
The minimum energy a collision must have for particles to react; a catalyst provides an alternative route with lower activation energy.
The minimum energy colliding particles need for a successful reaction, shown as a vertical line on the energy axis.
The energy, Ea, marked on the energy axis; the area beyond it is linked to the rate of a reaction.
The minimum energy that colliding particles must possess for a reaction to occur.
The minimum energy colliding particles must possess for a reaction to occur.
The minimum energy that colliding particles must have in order to react.
Topics that use Activation energy
- Collision theory (AQA A-Level)
- Enthalpy changes (OCR A-Level)
- Reaction rates (OCR A-Level)
Related terms
- successful collisions
- transition state
- ∆H of combustion
- ∆H of formation
- Alternative reaction pathway
- Approximate estimate
- Average bond enthalpy
- Averaging over gaseous compounds
Using Activation energy in the exam
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