50.0mL of a 1.00X10^-2M HNO2 is titrated with 1.00X10^-2M NaOH.?

Question

a) Calculate pH of solution before any base addition
b) calculate the pH after 18.39 mL addition of NaOH
c) Calculate the pH half way to the equivalence point
d) Calculate the pH at the equivalence point
e) Calculate the pH 0.68 mL after the equivalence point

Answer 1

HNO2 is a weak acid with Ka=4.5*10^-5. You ought to give this info in the question.
So you have a weak acid problem to solve for a, buffer for b, c,e and hydrolysis for d.

It requires a quite big answer; if I have the time to do it I'll edit this answer and include the solution

OK the answers are

a) pH=3.19
b) pH=4.13
c) pH=4.36
d) pH=8.02
e) pH=9.83

I hope I haven't done any numerical errors.
The solution is very big, so if you want you can send me your e-mail address and I can send you the solution as a .doc file

Answer 2

1. 3.30pH

2. 2.34pH

3 2.48pH

4. 7pH

5. 10.83pH