Different kinds of reactions What are the nonreactive cmpds there for ?

[Lo.Lee.Ta.]

There are many different kinds of reactions, but it seems evey one of them has these extra compounds on the reaction arrow (→) that don't even do anything...
They say they are catalysts or whatever, but what are they even doing?

For instance, I was writing out what the product is from 1-hexyne with H20 and H2SO4 and HgSo4.

They call this sort of reaction a keto-enol tautomerism reaction.

So first it produces an enol, and then it rearranges to form a keto tautomer.
But really, the H2O is the only thing here that actually reacted to form a new product. The O and the 2 H'S that got added were only from the H2O.

So what is the point of the other stuff in the reaction? I don't see how the H2SO4 or the HgSO4 did anything here... I guess this reaction would not have taken place without them, but WHY NOT?

Thanks for responding! You're awesome! :)

 

[AGNuke]

What you see in the textbook is the overall reaction. To understand what you are asking, you need to see the "mechanism" of the reaction.

First of all, in organic chemistry, they may represent the reactants for some intermediate step. They may represent solvent. They may represent normal reactant. They may represent catalyst as well.

Most reactions are not a single-step reaction, but they are a summation of different intermediate steps. And the reactants on the arrows are necessary in some reactions are required in a step, without which, the reaction will not proceed.

Also, in organic chemistry, people tend to write any reactant other than the sample reactant (the one on which we are doing problem) on the arrow. So, don't bother about the on-arrow reactant being a catalyst.