Subtopic: Bio-fuels and their use in farm mechanization
Question Statement:
In the chemical transesterification of non-edible vegetable oil (triglycerides) with methanol to produce fatty acid methyl esters (biodiesel), the theoretical stoichiometric molar ratio of methanol to triglyceride is:
Options:
(A) 3:1
(B) 1:1
(C) 1:3
(D) 6:1
Answer Key:
A
Step-by-Step Solution & Explanation
One molecule of triglyceride contains three fatty acid ester chains attached to a glycerol backbone. Complete transesterification requires 3 moles of alcohol (methanol) per mole of triglyceride to produce 3 moles of fatty acid methyl ester (biodiesel) and 1 mole of glycerol by-product (in commercial practice, an excess of 6:1 is used to drive the reversible reaction forward).