Question

A 30 mL solution of 0.200 M Ethylene diamine (C2H8N2) was titrated with a 0.210 M solution of HCl.
Calculate the pH values for each addition of HCl added during titration. C2H¬8N2 has a Kb=8.3 x 10-5.


1) 0.00 mL of HCl added
2) 5 mL of HCl added

3) 10 mL of HCl added

3) 10 mL of HCl added










4) 20 mL of HCl added
5) 28.6 mL of HCl added
6) 30 mL of HCl added

7) 35 mL of HCl added.
8) 50 mL of HCl added.

Answer 1

Now, you need to write down the equation of the reaction that is taking place during the titration.
Then you will work out the amounts in reaction for all values of added HCl solution.

Most of the answers will be given by either :
- coexisting amount of amine and ethylammonium ion
- or amount of excess H3O+.

Do this first, and we will work on the remaining cases later.