## effect of amount of catalyst in a reaction

 Quote by Borek In most cases yes, but not necessarily - for example for the second order reaction if you change both concentrations in such a way their product stays the same, reaction rate doesn't change.
Meaning in the example i gave the rates of reaction will change? But if the volume is changed such that the products is the same then the rates will be the same?
 Admin Which example? Assuming you have a reaction A + B -> C $$v = k [A] [B]$$ 0.5*0.5=1*0.25 so if you have both concentrations of 0.5M or one of 0.25M and the other of 1M, initial speed will be identical in both cases.

 Quote by Borek Which example? Assuming you have a reaction A + B -> C $$v = k [A] [B]$$ 0.5*0.5=1*0.25 so if you have both concentrations of 0.5M or one of 0.25M and the other of 1M, initial speed will be identical in both cases.
Hi Borek, I meant this example:What if my original concentrations are 0.5mol/dm^3 for both, but after adding then my concentration of one of the reagents increased to 0.67 while the other decreases to 0.33? Then how do I tell the rates of reaction? Thanks for the help!

Thanks for the help! BTW what is the name of that formula? Thanks!