[Ivybound04]

Consider the titration of 100.0 mL of 0.100 M H2NNH2 (Kb = 3.0  10-6) by 0.200 M HNO3. Calculate the pH of the resulting solution after the following volumes of HNO3 have been added.
(a) 0.0 mL (i've tried this 3 times and have gotten 8.48, 9.26, 13)
 
(b) 20.0 mL
 
(c) 25.0 mL
 
(d) 40.0 mL
 
(e) 50.0 mL
 
(f) 100.0 mL

A 25.0 mL sample of 0.100 M pyridine (Kb for pyridine is 1.7  10-9) is titrated with 0.100 M HCl solution. Calculate the pH after the addition of the following amounts of HCl.
0.0 mL (i've tried this 3 times and have gotten 3.12, 2.61, 10.885)
 
4.0 mL
 
8.0 mL
 
12.5 mL
 
20.0 mL
 
24.0 mL
 
24.5 mL
 
25.0 mL
 
26.0 mL
 
28.0 mL
 
30.0 mL


I don't even know where to start.  Please help.

[mithrilhack]

Try to calculate how much hydrogen/hydroxide ions are released for each substance.

[Ivybound04]

The problem is that I don't even know how to set up the rxn equation.  

[Borek]

(a) 0.0 mL (i've tried this 3 times and have gotten 8.48, 9.26, 13)

All three results are wrong. Show us what you have tried so that we can point out your mistakes
 
Both cases are simple neutralization reactions of strong acid and weak base.

There are many courses on the web describing how to make the calculations in such case. Take a look at my website (see footer) and follow links from FAQ section.

My BATE will give you fast results (but no comprehension!) so you can use it to check results once you will be able to do the calculations by yourself.