Find the pH of the two equivalence points and the volume (mL) of 0.527 M HNO3 needed to reach them in the titration of 0.188L of 0.250 M ethylenediamine (H2NCH2CH2NH2).

Question

cuanchi · Answer

you will need the  pKb for the two amine 
                                          pKb
Ethylenediamine (1)	20C	10.08	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Ethylenediamine (2)	20C	6.99

cuanchi · Answer

pKa pK1 7.56 pK2 10.71 http://www.inchem.org/documents/sids/sids/Ethylenediamine.pdf

cuanchi · Answer

then you have to write down the equations and figure out the dissociation and the concentration of H+ in each case.

thefurball · Answer

I found  89.2 as mL of first HNO3 and 5.34 as the first pH

How do I find the second equivalence point stuff?

cuanchi · Answer

the second equivalence point you supposed to use the second dissociation constant and replace the OH (because this is a base) with the [OH] from the first equilibrium that supposed to be bigger than the second.
 I think the volume to reach the second eq point will be the same, so if you used 89.2 ml for the first eq point you will need 89.2ml to reach the second eq-point.

vera_ewing · Answer

What do you not understand about the question?

cuanchi · Answer

see attachment for a similar problem solution

anonymous · Answer

what is the answer . can i have it