Question

Which of the following pair of compounds can be distinguished by iodoform test? 

Methanol and ethanol

Answer 1

	Methanol	Ethanol
1.	Methanol is a primary alcohol with only one carbon atom.	Ethanol is a primary alcohol with two carbon atoms.
2.	On oxidation, methanol gives formaldehyde (HCHO), which lacks the CH3–CO– group.	On oxidation, ethanol gives acetaldehyde (CH3CHO), which contains the CH3–CO– group.
3.	Formaldehyde does not undergo the iodoform reaction.	Acetaldehyde undergoes the iodoform reaction.
4.	Methanol does not give a yellow precipitate of iodoform (CHI3).	Ethanol gives a yellow precipitate of iodoform (CHI3).
5.	Methanol gives a negative iodoform test.	Ethanol gives a positive iodoform test.
6.	Methanol cannot be detected by the iodoform test.	Ethanol can be detected by the iodoform test due to CHI3 formation.