Temperature dependence of Kc
What Temperature dependence of Kc means in Chemistry A-Level, as defined for OCR.
Definitions of Temperature dependence of Kc
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Reference: OCR
Changing temperature alters the value of Kc itself: for an exothermic forward reaction, raising temperature lowers Kc and shifts equilibrium towards reactants, whereas for an endothermic reaction the opposite occurs.
The value depends only on temperature, so changing concentration, pressure or adding a catalyst does not change it at a fixed temperature.
Only a change in temperature alters Kc, because it changes the value of ΔG° and hence the position of equilibrium.
Kc depends only on temperature for a given reaction, so the magnitude is compared at a stated temperature.
Topics that use Temperature dependence of Kc
- Chemical equilibrium (OCR A-Level)
- How far? (OCR A-Level)
Related terms
- Le Chatelier's principle
- Calculating Kc from equilibrium concentrations
- closed system
- constant concentrations
- Constant temperature and constant titre
- Controlling variables in equilibrium experiments
- Conversion between moles, concentration and partial pressure
- Determination of units by unit cancellation
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