Chemistry · Chemistry of Life
Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive drills and topic analytics.
The extent of un-saturation in a fat is expressed as its:
- A
Acid number
- B
Iodine number
- C
Saponification number
- D
None of these
Iodine value, also called Iodine Number, in analytical chemistry, a measure of the degree of unsaturation of oil, fat, or wax; the amount of iodine, in grams, that is taken up by 100 grams of the oil, fat, or wax.
a) Acid Number: The acid number of a fat refers to the amount of free fatty acids present in the fat. It is a measure of the acidity of the fat and does not directly relate to the extent of unsaturation.
b) Iodine Number: This is the correct option. The iodine number, also known as the iodine value or iodine index, is a measure of the extent of unsaturation in a fat or oil. It represents the amount of iodine (in grams) that is absorbed by 100 grams of fat. Unsaturated fats, which have double bonds in their fatty acid chains, can react with iodine, leading to a higher iodine number. The higher the iodine number, the more unsaturated the fat.
c) Saponification Number: The saponification number is a measure of the average molecular weight of a fat. It represents the number of milligrams of potassium hydroxide (KOH) required to neutralize the fatty acids liberated from 1 gram of fat. It is used to characterize the molecular weight of fats and does not directly relate to the extent of unsaturation.
d) None of these: This option suggests that none of the mentioned terms (acid number, iodine number, saponification number) express the extent of unsaturation in a fat. However, as explained above, the iodine number is specifically used to quantify the extent of unsaturation in a fat.
Tagged under Chemistry · Chemistry of Life · 2008