Chemistry A-Level
active sites
What active sites means in Chemistry A-Level, as defined for AQA.
Definitions of active sites
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Reference: AQA
Reactant molecules are adsorbed onto these sites on the surface, which weakens their bonds, holds them in the right orientation and raises their concentration at the surface.
The places on the surface of a heterogeneous catalyst where the reaction happens, and their number per gram of metal rises sharply with a support.
Topics that use active sites
- Catalysts (A-level only) (AQA A-Level)
Related terms
- autocatalysis
- catalyst
- catalytic converters
- economic consequences
- Haber process
- intermediate species
- ion repulsion and high activation energy
- iron catalyst
Using active sites in the exam
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