Iodine + Saturated Fats in Oils HELP!

[Limobean]

In this experiment

http://www.all-science-fair-projects.co ... t_1143_129

their timed results were converted into a percentage.
Eg. For Peanut Oil,
It took 38seconds and they converted it to 38% saturated fat. How did they do that? (Refer to observation on the webiste for results)

Does anyone know what calculation they used? If so how?

Also, it would also be better if I could calculate the exact amount of saturated fat. Is that possible?
How do you calculate the amount of saturated fat in an oil from the time it takes to clear the iodine?

If you don't know how, is there a recommended site I should visit to try and find this out?
Please, I need this calculation and can't find it out?!
Thanks!!

[Limobean]

Hi, I am interested in doing this experiment:

http://www.all-science-fair-projects.co ... t_1143_129

but I have no idea how they did their calculations. How did they convert the time it takes for the iodine to discolourise, into a quantitative measurement (percentage)?
Also is it possible to convert the time it takes for the iodine to discolourise into the number of grams of saturated fat? If so how? What is the calculation?

Is there a site which I could possibly find how to do that?

If not, what other different calculations could I make from this assignment? Maybe the number of iodine drops can be converted inot number of grams of saturated fat?

Thanks so much! This is due so soon and I need the answers quickly!

[John Dreher]

Welcome to the Forum Limobean.

You are confused because the description of the project given at the cited web page is very misleading.
They did NOT calculate the percentage of saturated fat from the time to clear the iodine staining -- they used the data in the first table of the first reference given in their bibliography. Their statement of their hypothesis is incorrect. Their hypothesis is actually something like "the time to clear the iodine staining in the oil goes up with the percentage of saturated fat in the oil". The independent variable is really the percent saturated fat (obtained from the reference cited in their 'References'). The dependent variable is the time to clear the iodine-induced color. They do not calculate the percent saturated fat at all. They do not even plot the time versus the percent fat! A very shoddy writeup indeed. I would give it a C-

For your report I suggest you use their table but fill in the times from your data. If you want to make this a more polished effort, add a graph of time versus percent saturated fat. Also, ideally you would test each oil at least three times to see how accurately you can measure the time-to-clear; plot all three (or more) points on an x-y graph (not a bar graph), then add points for the average and run a line between the average value points. That way the reviewer can see the uncertainty of each point as well as the best estimate (the average). Finally, point out the error in the hypothesis in the write up, but use cautious wording, something like: "I believe a better description of the hypothesis and the independent variables would be ..." so as not to be offensive.

Sorry you ran into this. Best luck on your report.

[Limobean]

Oh...right. WOW. OK Thanks for feedback. I'm no longer doing this experiment anymore then, but a similar one, except instead of measuring time, I'm measuring the number of drops of iodine used for it to discolour completely.

But I can't seem to find any experiments online that give results, because I need to compare my results with the experiment online to back mine up.

Are theere any sites? I've looked at so many and many only post the procedure with no results.

[John Dreher]

Well, I do not understand what you mean when you say "discolour completely". Could you please clarify so that I can help you?

Also, I stumbled across a web site that has a correct description of the original project. It's URL is

http://tinyurl.com/ccjq33a

Best wishes,

John

[Limobean]

Never mind, I am no longer doing his experiment.