Biomolecules and Chemistry in Everyday Life - Result Question 26
27. For ‘invert sugar’, the correct statement(s) is (are) (Given: specific rotations of $(+)$ - sucrose, $(+)$ - maltose, $L-(-)$-glucose and $L-(+)$-fructose in aqueous solution are $+66^{\circ},+140^{\circ},-52^{\circ}$ and $92^{\circ}$, respectively)
(2016 Adv.)
(a) Invert sugar is prepared by acid catalysed hydrolysis of maltose
(b) Invert sugar is an equimolar mixture of $D-(+) -$ glucose and $D$ $-(-)-$ fructose
(c) Specific rotation of invert sugar is $-20^{\circ}$
(d) On reaction with $Br _2$ water, invert sugar forms saccharic acid as one of the products
Show Answer
Answer:
Correct Answer: 27. (b, c)
Solution:
- If there is inversion of specific rotation from $(+)$ to $(-)$, then invert sugar is formed.
(a)
(b)
There is formation of invert sugar. Thus, correct.
(c) Specific rotation of invert sugar is $-20^{\circ}$ per mole. Thus, correct.
(d) $Br _2$ water is a weak oxidising agent. It oxidises $-CHO$ to $-COOH$. $- CH _2 OH$ group is not affected.
$HNO _3$ (a strong oxidising agent) oxidises invert sugar to saccharic acid. Thus, incorrect.
BETA
