wonders

I don't really get what you mean. What does solubility have to do with change in temperature?

what causes the temperature increase?

My teachers wants us to design the lab ourselves. She gave us the materials and purpose, and we plan it. -sigh-

I don't know if that's the same thing my teacher meant. How do you use that method to identify unknown substances (aq) though? The example she gave us is: suppose NaBr (s) --> Na+ (aq) + Br- (aq) AgNO3 (s) --> Ag+ (aq) + NO6- (aq) If the solutions are mixed, Na+ (aq) + Br- (aq) + Ar+ (aq) + NO3- (aq) --> AgBr (s) AgBr (s) is the precipitate, so what is in the mixture will be: AgBr (s) + Na+ (aq) + NO3-(aq) So now for the experiment we are given reagents KOH and H2SO4 to identify unknown substances. How do you apply her example in this case?

Yes, I do know what reagents are. But I don't know how to conduct an experiment with them. The teacher gave us KOH (aq) and H2SO4 (aq) and asked us to use them to identify unknown substances. I have no idea what I should do. Sorry if that doesn't make any sense to you.

And what are the purposes of doing tests with reagents?

Thanks guys!

Argh, I'm starting to confuse elements with atoms, and homogeneous mixtures with molecules. Is it like that: Molecules contain elements which contain atoms which contain ions? Molecules ---> Elements ---> Atoms ---> Ions?

1. Just in general? 2. In chemical properties? Thanks in advance!