What is the iodoform test and its significance?

The iodoform test is a chemical reaction used to identify the presence of methyl ketones (compounds containing the CH₃CO- group) and secondary alcohols with at least one methyl group in the alpha position. When a compound containing these groups is treated with iodine and sodium hydroxide, a yellow precipitate of iodoform (CHI₃) is formed, which is indicative of a positive test.

This test is significant because it helps in distinguishing methyl ketones and methyl-containing secondary alcohols from other functional groups. It is commonly used in organic chemistry for qualitative analysis.