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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: pHysiX on May 07, 2009, 07:47:54 pm

Title: Catalysts
Post by: pHysiX on May 07, 2009, 07:47:54 pm

I have just a simple question.

In the reaction of salicylic acid and ethanoic anhydride, sulfuric acid is added. This is a catalyst and is not a reactant.

My question is:
How do we prove that it is a catalyst?

I was thinking of reacting the salicylic acid and ethanoic anhydride normally and note the time for the reaction to be complete.

Thanks heaps in advance =]

Title: Re: Catalysts
Post by: TrueTears on May 07, 2009, 07:50:29 pm

Quote from: pHysiX on May 07, 2009, 07:47:54 pm

I was thinking of reacting the salicylic acid and ethanoic anhydride normally and note the time for the reaction to be complete.

You are thinking exactly the same thing as me atm. LOL

Title: Re: Catalysts
Post by: iamdan08 on May 07, 2009, 08:07:34 pm

...and perhaps that it is not consumed in the reaction.

Title: Re: Catalysts
Post by: iamdan08 on May 07, 2009, 09:05:16 pm

Another way you could further prove it was a catalyst is that the change in enthalpy of the reaction would be the same, since catalysts only affect the activation energy. You could measure this by measuring the energy released before and after it was added.

Title: Re: Catalysts
Post by: Gloamglozer on May 08, 2009, 10:16:09 pm

I think you can prove it was a catalyst by titrating the catalyst.  Don't quote me on it but I'm just putting it out there on the table.

Title: Re: Catalysts
Post by: pHysiX on May 09, 2009, 07:43:52 pm

i've talked to a few people and i think the best way is to:

do the reaction without catalyst and note the time.
then we can do a titration to verify the amount of catalyst in the solution.

thanks guys for the help =]