Science Buddies: "Ask an Expert"

Hello,

I was trying to do the iodine starch reaction for a project but it didn't work! I used Morton Iodized salt which should have iodine in it but when I added in the white vinegar, hydrogen peroxide, and laundry starch it turned yellow indicating that it has no iodine!!


Help!!

Hello!

I agree with you that the iodized salt should have had a reaction. However, since it did not, I would assume that there was an error(s) in the materials or in carrying out the procedures. Common errors are the hydrogen peroxide is not 3% hydrogen peroxide, measurements are done incorrectly, and steps are done out of order. If you have not done so already, I would recommend checking all of the materials and doing more trials to see where the error lies.

I hope that helps! Ask again if you continue to have problems.

-Kayli

Hi!

My science fair is tomorrow and I have 1 question. What does it mean when Iodine turns the solution completely purple? I know that the purple indicates that there is iodine. I am testing the amount of time it takes the whole iodine starch solution to turn purple if that makes any sense!

Help!!

Moderator note: I merged this question with your previous post, that way the expert who has been helping you is more likely to see your new question and help you! Thanks!