Basic Chemistry guide websites?

Question

I am taking O-chem right now and need to remember some of the basic stuff from general chemistry such as finding molarity, pH, etc etc.
Unfortunately, I took general chemistry freshman year and I am now a senior, so everything is a little rusty.

Any basic websites with formulas/tips etc will be greatly appreciated. Best one gets the 10 points!

Answer 1

wikipedia.
wikipedia.
wikipedia!

MIT Opencourseware might be helpful also.

Google search.