Question

Which of the following helps in the classification of oils into drying, semi-drying and non-drying categories?

(a) Acid number

(b) Iodine number

(c) Saponification number

(d) Richert-Meissl number

This question was addressed to me in quiz.

This interesting question is from Oils and Fats topic in division Industrially Important Materials of Engineering Chemistry II

Answer 1

Right choice is (b) Iodine number

Easiest explanation: Iodine number helps in the classification of oils into drying, semi-drying and non-drying categories. 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.