The Student Room Group

Temperature ,rate constant k and rate ??

Hi guys ,I've been going over kinetics (Chemistry unit 4 AQA) And im confused about how the effects of changing conditions on the rate constant and the normal rate of reaction.
So far I've read that the rate constant k is only affected by temperature and nothing else (sometimes by a catalyst).But the rate of reaction can be affected by pressure ,concentration etc.Why is this so?


Posted from TSR Mobile
The rate equation is

Rate = K [A]xy

So the only things which affect rate are the concentrations and K and if the rate changes one or both of these must change.
If we change rate by changing the conc (pressure for gases) then K remains constant but if we change the rate using temp (or some catalysts) then the conc of reactants remains the same so K is changing. If we raise the temp then the rate always increases so K increases with temp.

Hope this helps

Quick Reply

Latest