The
iodine value (or "iodine adsorption value" or "iodine number" or "iodine index") in
chemistry is the mass of
iodine in grams that is consumed by 100 grams of a
chemical substance. Iodine numbers are often used to determine the amount of unsaturation in
fatty acids. This unsaturation is in the form of double bonds, which react with iodine compounds. The higher the iodine number, the more C=C bonds are present in the fat. It can be seen from the table that
coconut oil is very saturated, which means it is good for making
soap. On the other hand, linseed oil is
highly unsaturated, which makes it a
drying oil, well suited for making
oil paints.