Which set lists only the alkaloidal reagents II, III, and IV as true?

Which set lists only the alkaloidal reagents II, III, and IV as true?

• A. I, II, III
• B. I, III, IV
• C. I, II, IV
• D. II, III, IV

Answer: (D)

Alkaloidal reagents detect alkaloids by forming insoluble salts or complexes with the basic nitrogen in alkaloids, producing a visible precipitate that signals presence. Among the reagents listed, three are known to act as true alkaloidal reagents and will give this characteristic precipitate with alkaloids, while the remaining one does not. So the only set that includes exactly the alkaloidal reagents is the one that lists those three and excludes the non-alkaloidal reagent. This reflects the idea that these tests are specific for alkaloids, whereas the reagent that isn’t an alkaloidal reagent wouldn’t reliably indicate alkaloids.

Alkaloidal reagents detect alkaloids by forming insoluble salts or complexes with the basic nitrogen in alkaloids, producing a visible precipitate that signals presence. Among the reagents listed, three are known to act as true alkaloidal reagents and will give this characteristic precipitate with alkaloids, while the remaining one does not. So the only set that includes exactly the alkaloidal reagents is the one that lists those three and excludes the non-alkaloidal reagent. This reflects the idea that these tests are specific for alkaloids, whereas the reagent that isn’t an alkaloidal reagent wouldn’t reliably indicate alkaloids.