Question

Choose the correct statement from the following:
(P) Anthraquinone derivatives are generally detected by Borntrager’s test
(Q) Anthrone is yellow colored and soluble in alkali
(R) Anthranol is insoluble in alkali and shows strong red fluorescence
(S) Borntrager’s test gives negative result with Anthranol (Reduced form)

• A. $ \text{P and S Only} $
• B. $ \text{R Only} $
• C. $ \text{Q and R Only} $
• D. $ \text{P Only} $

Hint:

Borntrager’s test is positive for free anthraquinone glycosides, not their reduced forms like anthranol.

Answer 1

The Correct Option is A

- [P]: True. Borntrager’s test is a qualitative test to detect free anthraquinone glycosides, giving a pink to red color in the ammoniacal layer.
- [Q]: False. Anthrone is typically greenish in color and used as a reagent, not a yellow compound.
- [R]: False. Anthranol, being a reduced form, is soluble in alkali and generally does not show red fluorescence.
- [S]: True. The reduced form (like anthranol or anthranone) gives a negative Borntrager’s test, since oxidation is needed to yield the colored anthraquinone compound.

Answer 2

This question lists four statements, P, Q, R and S, about anthraquinone derivatives, anthrone and anthranol, and asks which combination of these statements is correct. Each answer option below is checked against the actual chemistry of these compounds.

1. P and S Only: Statement P says Borntrager's test detects anthraquinone derivatives, which is correct: the test relies on oxidised, free anthraquinones giving a pink to red colour in an alkaline layer. Statement S says the test gives a negative result with anthranol, the reduced form, which is also correct, because anthranol must first be oxidised back to the quinone form before the colour reaction can occur. Since both P and S hold, this combination is fully supported.
2. R Only: Statement R claims anthranol is insoluble in alkali and shows strong red fluorescence. In reality, anthranol, like other phenolic reduced anthracene derivatives, dissolves readily in alkali, so this statement does not hold, and this option cannot be correct.
3. Q and R Only: Statement Q claims anthrone is yellow and soluble in alkali; anthrone is actually a colourless to pale compound used as a reagent, for example in the anthrone test for carbohydrates, and is not the yellow, alkali-soluble form described here. Combined with the already false statement R, this option fails on both counts.
4. P Only: This option correctly credits P but leaves out S, which is also a true statement, so restricting the answer to P alone is incomplete.

Working through all four statements shows P and S are the only two that match the established chemistry of anthraquinones and their reduced forms, while Q and R do not.

Therefore, the correct answer is P and S Only.