SCIENCE FAIR EMERGENCY

[needsciencehelp]

Hi

im doing a science fair and its due sep. 26. my topic is Saturated fat levels in different varieties of cooking oils and i need help. i was doing research and i realized the oils were unsaturated. my experiment is i have 5 different cooking oils and im measuring saturated fat levels. i put three drops of iodine into a oil and time it to see how long it will take for it to turn clear again. i learned that As iodine reacts with unsaturated oil to lose its color, a lower proportion of unsaturated oil content will require a longer reaction time for the iodine in the oil to lose its color. why???? also, what type of iodine do i use??? omg i need help ASAP. thanks:)

[mbadtke]

Needsciencehelp,
The link below will answer some of your questions about why iodine is used to show the amount of unsaturated fats.

http://www.chemistryexplained.com/Di-Fa ... Acids.html

If you look around on the net there are probably established values for the iodine that will react with certain oils. You could use that to help ensure you are on the right track. One important thing to remember is you need to use the same weight of oil for all your samples. Good luck with your project!

Matt Badtke

[needsciencehelp]

kay, thanks! but i still dont get why this experiment will show SATURATED fat levels. also are you aware which iodine is to be used. is it 7% tincture, etc.

[needsciencehelp]

omg. i was on a website and i think(not really sure) i found out why As iodine reacts with unsaturated oil to lose its color, a lower proportion of unsaturated oil content will require a longer reaction time for the iodine in the oil to lose its color. the reason is that As you increase the number of double bonds in a fatty acid, you reduce that ability for oils to gain a conformation that would make them solid, so they remain liquid. so it will be easier for the iodine to go through the higher number of double bonds because its liquid! right?? becuz im only a 9th grader w/o chemistry.

[needsciencehelp]

the website is http://journeytoforever.org/biodiesel_yield.html#iodine

[aelin]

Hi,

I think it might be a little simpler than that. Fats are either saturated or unsaturated, so if you measure unsaturated fat levels, that tells you saturated fat levels. Unsaturated means that the fat has double bonds, which can react with iodine. When you add iodine to unsaturated fats, the iodine decolorizes and the double bond is broken, creating a saturated fat (so decolorization is a measure of number of double bonds or unsaturation).

[sk1]

Hi Needsciencehelp,

What your describing right now has to do with reaction kinetics and a little bit of organic chemistry, which is something that is probably beyond your level. Double bonds tend to be very reactive and if you add iodine to unstaturated fats, the iodine will break the double bonds between the fats and the iodine molecule will attach to the broken fat. As for reaction kinetics, the more unstautrated fats you have in the oil, the faster you will be the iodine disappear.

Hope that helps!

-Sam

[needsciencehelp]

thank you so much!! this really helped!