vit c test
Posted: Fri Mar 24, 2006 11:34 am
added oj to iodine starch mix, why does liq change to clear? how is this dif from iod added to oj?
Here is a quick explanation I found from
http://tiger.coe.missouri.edu/~pgermann ... min_c.html
"Scientists use chemicals to determine the presence of other chemicals. These chemicals are called indicators -- they make an observable physical change -- usually color when mixed with another specific chemical. Iodine changes from red/brown to dark blue-black in the presence of starch. The two together in a solution can be used as an indicator of Vitamin C (ascorbic acid). Iodine binds to starch. Iodine also binds to ascorbic acid. When it binds to vitamin C, it is colorless. Iodine binds more strongly to ascorbic acid than it binds to starch. The iodine, therefore, leaves the starch and binds to ascorbic acid, which would make the blue solution become clear."
Post if you have more questions.
Sonia