Science Buddies: "Ask an Expert"

How would you measure iodine in salt?

I found some iodine test strips on this website: (Science Buddies has never ordered from them before, so we cannot vouch for the company's quality of service). http://www.indigo.com/test-strips/gph-t ... trips.html

You just dip them into a solution with iodine (in your case water and salt), and by the color that shows up on the strip you can determine the approximate concentration of iodine. This isn't a very accurate method, but depending on your project this accuracy might be all you need.

You should check to see if these strips would be sensitive enough. If the amount of iodine is too high or too low for the strips to measure, you won't be able to distinguish between different concentrations. You want to be sure you can realistically dilute the concentration of the salt without adding liters of water to get within the test strip's range. (Make sure as you are doing this experiment that you keep track of how much water you add so you can figure out the concentration).

Let us know if you have other questions. Good luck!