Question

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

Methanol and butan-1-ol

Answer 1

	Methanol	Butan-1-ol
1.	Methanol is a primary alcohol with only one carbon atom.	Butan-1-ol is a primary alcohol with four carbon atoms.
2.	On oxidation, methanol gives formaldehyde (HCHO), which lacks the CH3–CO– group.	Butan-1-ol gives butanoic acid, which also lacks the CH3–CO– group.
3.	Formaldehyde does not contain the required CH3–CO– group.	Butanoic acid also does not contain the CH3–CO– group.
4.	Methanol does not have the CH3–CH(OH)– structure required for the test.	Butan-1-ol also lacks the CH3–CH(OH)– group necessary for the test.
5.	Methanol does not give a yellow precipitate of iodoform (CHI3).	Butan-1-ol also does not give a yellow precipitate of iodoform (CHI3).
6.	Methanol gives a negative iodoform test.	Butan-1-ol also gives a negative iodoform test.
7.	No yellow precipitate of iodoform (CHI3) is formed when methanol is tested.	No yellow precipitate of iodoform (CHI3) is formed when butan-1-ol is tested.
8.	Methanol cannot be detected using the iodoform test.	Butan-1-ol also cannot be detected using the iodoform test.