I did a separation of Bromide and Iodide ions using paper chromatography technique for 0.3% solutions of Bromide and Iodide of sodium. I got the Retention factor equal to ~0.71 for Iodide and ~0.47 for Bromide.

So, I want to ask if ion size is playing any role in deciding this retention factor? Or, is there some another perspective that I am missing here? Specifically, what is the reason for this difference?

  • $\begingroup$ Asking this way is not how this site works. Answers on CH SE site are figuratively paid by the user's own effort. Before asking, you are supposed to think, search, read, think, think more. If you still fail to find the answer, then ask, but together with explicit compact summary of ideas a/o results you got until then. $\endgroup$
    – Poutnik
    May 27 at 6:33
  • $\begingroup$ @Poutnik, I have researched on the web and most of the articles say that solvent plays a role. Here, I took the same solvent. So, I was wondering if ion size plays a role or not as I wasn't able to find a convincing source stating the same. If you get one, do let me know. And saying a user that he hasn't done any research without knowing what he has done, prior to asking... is rude. $\endgroup$
    – Sanu_012
    May 27 at 6:39
  • $\begingroup$ I have not said so, so I reject accusation to be rude. Effort not shown is effectively effort not done. I could say I have been searching libraries and internet for weeks and still do nothing. Readers expect some evidence of your effort. Even if you found nothing, you are still expected to present your ideas about it. $\endgroup$
    – Poutnik
    May 27 at 7:18
  • $\begingroup$ Generally, ion radius plays a role in most processes where ions are involved. Why should Rf be exception ? Have you considered electrostatic interations of ions and cellulose polar OH bonds ? $\endgroup$
    – Poutnik
    May 27 at 7:37
  • $\begingroup$ That's what I was wondering, @Poutnik. I guessed that ion radius must play some role in this case, but couldn't find anything regarding that. No, I didn't consider the interaction of ions and cellulose polar OH bonds yet. I will do it right away, and will let you know. $\endgroup$
    – Sanu_012
    May 27 at 7:44

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