Please wait...
1800-212-7858 (Toll Free)
9:00am - 8:00pm IST all days
For Business Enquiry


Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this toll free number


Mon to Sat - 11 AM to 8 PM

explain common ion effect with reference to GrIII precipitation of cations

Asked by ruchira121996 27th March 2013, 8:49 PM
Answered by Expert
The degree of ionization of an electrolyte is suppressed by the addition of a strong electrolyte containing common ion. This effect is known common ion effect.
In other words:
The phenomenon of lowering the degree of ionization of a weak electrolyte by adding a solution of a strong electrolyte having a common ion is called common ion effect.
Cations of groups IV are precipitated as sulphides by passing H2S gas through the solution in the presence of NH4OH.
  Ionization of NH4OH:
NH4OH NH4+ + OH-
In this analysis NH4OH provides OH- ions which combines with H+ ions of H2S to form H2O.
H2 2H+ + S-2        :       H+ +  OH-   H2O
Removal of H+ ions from product side shifts the equilibrium to right and the concentration of S-2 increases which is enough to exceed the KSP of the sulphides of group IV. In this way CoS, NiS or ZnS can easily be precipitated.

Answered by Expert 28th March 2013, 6:30 AM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Your answer has been posted successfully!

Chat with us on WhatsApp