Biomolecules Question 6
Question 6 - 30 January - Shift 1
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Ketoses give Seliwanoff’s test faster than Aldoses.
Reason (R) : Ketoses undergo $\beta$-elimination followed by formation of furfural.
In the light of the above statements, choose the correct answer from the options given below :
(1) (A) is false but (R) is true
(2) Both (A) and (R) are true and (R) is the correct explanation of $(A)$
(3) (A) is true but (R) is false
(4) Both (A) and (R) are true but (R) is not the correct explanation of (A)
Show Answer
Answer: (3)
Solution:
Formula: Seliwanoff’s Test and Beta Elimination
Seliwanoff ’s test is a differentiating test for Ketose and aldose. This test relies on the principle that the keto hexose are more rapidly dehydrated to form 5-hydroxy methyl furfural when heated in acidic medium which on condensation with resorcinol, Cherry red or brown red coloured complex is formed rapidly indicating a positive test.
