Which one of the following is an appropriate indication of positive iodoform test?
Correct answer: D. Yellow crystal
- A. Formation of H2O
- B. Release of H2 gas
- C. Brick red precipitate
- D. Yellow crystal
Explanation
The formation of yellow crystals is an appropriate indication of a positive iodoform test. When a compound containing a methyl ketone or secondary alcohol group undergoes the iodoform test, it reacts with iodine and a base to form iodoform (CHI3) as a yellow precipitate. This yellow precipitate is often observed in the form of yellow crystals, indicating a positive result for the presence of the functional groups targeted by the iodoform test.
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About Aldehydes and Ketones
Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.
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