[Violagirl]

In general when writing out lab reports for O Chem lab (or for any chem lab), how much information is sufficient for writing out the purpose? I know that the goal of the experiment should be listed and a summary of techniques and analytical methods should be included. When talking about the reation itself, is it necessary to specify what reactants are used for, i.e. to mention when reagent is used as a catalyst or as a base to promote said reaction? Or can that be discussed later when the mechanism is explained?

[Dan]

It depends on who is marking the report and which institution it is. Ask whoever is going to mark it.

[Vidya]

your purpose should clearly and broadly  indicate the aim of doing the experiment .There is no need of mentioning any reagent or catalyst or procedure in the aim.It should be in brief in two to three sentences.

[Telamond]

I've noticed that this differs from university to university, and between departments and whoever is assigned to correct the lab report...

I usually give out a quick summary of how I want my lab reports written and formatted and I have no problem asking the students to resubmit the report as that format.
If I were to correct your report I'd have the Aim in 2-3 sentences like Uma said and the reactants are self-explained when you draw the mechanism. The assistant usually understands if you understood the purpose of each chemical you used by looking at the mechanism.

[Violagirl]

That helps a lot! The lab report I'm writing involved two different reactions so was curious if it would be essential to include each aspect of different reactants used for it. Thanks a ton!