Acid-Base Reactions

This is a relatively simple unit, so there aren't too many notes. Basically
Strong acids dissociate to produce H⁺ ions
Strong bases dissociate to produce OH^-  ions
However, when strong acids and strong bases mix you get HOH and ionic salt

And since you also know that pH is the measure of H ions present in a solution, you also probably know that pOH would be the measure of OH ions in a solution.
Thus
pH = -log[ H⁺ ]
pOH = -log [ OH^- ]

So here's an example to test you knowledge of the new concept while still incorporating past knowledge.

If  .100 L of .40M of HNO₃ is added to .300L of .20M of NaOH
First find the limiting reactant
0.1 x (.40mol)/(1L) x 1/1 x (1L)/(.20mol) = .2 L of NaOH is needed
(since you have .300 L of NaOH)  HNO₃ is the Limiting Reactant

Then find how much NaOH will be left over.
So you find how much NaOH you use, and how much HNO₃ you use.
(.3L) x (.2mol)/(1L) = .06 mol of NaOH used
(.1L) x (.4mol)/(1L) = .04 mol of HNO₃ used
You then subtract the amount of NaOH used from the amount of HNO₃ used
.06-.04 = .02 mol of excess HNO₃

Next find the pH
pH = -log [ H⁺ ]
      =  -log(.02)
pH = 1.7           (there are no units)

Not too difficult, right? Now if you can do a question like that then you fully understand Acid-Base reactions.
And just make sure you remember your significant digits and decimal points