Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1]   Go Down

Author Topic: How to obtain concentration of a FeG+ using activity coefficient?  (Read 3383 times)

0 Members and 1 Guest are viewing this topic.

Chaste

  • Full Member
  • ****
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 101

Equilibria involved :
FeG+ + G-  ::equil:: FeG2 K2 = 3.2 x 103
G- + H2::equil:: HG + OH- Kb = 6.0 x 10-5
G- is the amino acid glycine.
Suppose that 0.050 mole of FeG2 is dissolved in 1 litre of water.

Qns: Using activity coefficient, find FeG+ if the pH is fixed at 8.5 and the ionic strength is 0.10M. For FeG+, use gamma = 0.79. and for G- use gamma = 0.782

My attempt at the question:

MBE 1 = 0.05 = [FeG+] + [FeG2]
MBE 2 = [FeG+] = [HG] + [G-]

the ionic strength being 0.1,

0.1 = 0.5 x [FeG+] + [G-] + [H3O+] + [OH-]   ----- 1

and I'm stuck. I suppose I need to solve simultaneous equations. how do I make use of the pH and activity coefficients to resolve this question?
Logged

Pradeep

  • Regular Member
  • ***
  • Mole Snacks: +5/-3
  • Offline Offline
  • Posts: 95
Re: How to obtain concentration of a FeG+ using activity coefficient?
« Reply #1 on: December 16, 2010, 07:03:30 AM »

Can use debye-hukal law to relate the concentration and ionic strength.
Logged

Chaste

  • Full Member
  • ****
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 101
Re: How to obtain concentration of a FeG+ using activity coefficient?
« Reply #2 on: December 16, 2010, 03:23:26 PM »

hi there, thanks for the contribution. The question has been there for a while and it has been solved.
Logged
Pages: [1]   Go Up
 

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.053 seconds with 23 queries.