March 29, 2024, 04:57:21 AM
Forum Rules: Read This Before Posting


Topic: Test of iodine in salt with lemon  (Read 9360 times)

0 Members and 2 Guests are viewing this topic.

Offline jhernandezf

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
Test of iodine in salt with lemon
« on: April 13, 2008, 03:58:16 PM »
Hi
I made a test to look for iodine in salt.  I used one recommended by UNICEF  : Salt becomes purple when lemon juice is mixed with it.  Perfect, but I do not know why this occurs. Why lemon does that on salt.

Any help on this will be greatly appreciated

Thanks
Johanny

Offline english

  • Chemist
  • Full Member
  • *
  • Posts: 534
  • Mole Snacks: +31/-10
  • Gender: Male
  • grad student
Re: Test of iodine in salt with lemon
« Reply #1 on: April 13, 2008, 04:00:55 PM »
Isn't iodine solid purple?  Does this mean you're getting a deposition of iodine when you add lemon juice?  Possibly a redox reaction?

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Test of iodine in salt with lemon
« Reply #2 on: April 13, 2008, 04:54:03 PM »
Is there starch present, in your sample or your test reagent salt?  The iodine, is it free iodine (the brown or purplish-black crystals, with a lustrous almost metallic sheen) or is it a salt of iodine (can be white in color)?

*[EDIT]*

It appears you were performing a test, something like this one:
http://www.unicef.org/uzbekistan/reallives.html
but, some more specifics about your application are needed.
« Last Edit: April 16, 2008, 01:03:19 PM by Arkcon »
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Sponsored Links