A. propanol
B. ethanol
C. glycerol
D. methanol
Correct Answer:
Option C – glycerol
Glycerol is the common name of the organic compound whose chemical structure is HOCH2 CHOH CH2OH. Propane-1,2,3-triol or glycerin (USP), as it is also called, consists of a chain of three carbon atoms with each of the end carbon atoms bonded to two hydrogen atoms (C–H) and a hydroxyl group (–OH) and the central carbon atom is bonded to a hydrogen atom (C–H) and a hydroxyl group (–OH). Glycerol is a trihydric alcohol because it contains three hydroxyl or alcohol groups.
Glycerin is a thick liquid with a sweet taste that is found in fats and oils and is the primary triglyceride found in coconut and olive oil. It was discovered in 1779 when the Swedish chemist Carl Wilhelm Scheele (1742-1786) washed glycerol out of a heated a mixture of lead oxide (PbO) and olive oil. Today, it is obtained as a byproduct from the manufacture of soaps.
One important property of glycerol or glycerin is that is not poisonous to humans. Therefore it is used in foods, syrups, ointments, medicines, and cosmetics. Glycerol also has special chemical properties that allow it to be used where oil would fail. Glycerol is a thick syrup that is used as the “body” for many syrups, such as cough medicines and lotions used to treat ear infections. It is also an additive in vanilla extracts and other food flavorings.
Glycerin is added to ice cream to improve its texture, and its sweet taste decreases the amount of sugar needed. The base used in making toothpaste contains glycerin to maintain smoothness and shine. The cosmetic industry uses glycerin in skin conditioning lotions to replace lost moisture, relieve chapping, and keep skin soft. It is also added to shampoos to make them flow easily when poured from the bottle.
