Question

Formation of gluconic acid from glucose by oxidation using Br₂ water.

विकल्प

• glucose contains five hydroxyl groups.

• the presence of an aldehyde group in glucose.

• glucose contains one primary alcoholic group. 

• the six carbon atoms of glucose are in a straight chain.

Answer 1

the six carbon atoms of glucose are in a straight chain.

Explanation:

The carbonyl group in glucose is in the form of aldehyde. This was inferred from the observation that glucose gets oxidised to a six-carbon monocarboxylic acid called gluconic acid in reaction with bromine water which is a mild oxidizing agent.

\[\begin{array}{cc}
\ce{CHO}\phantom{.............}\ce{COOH}\phantom{..}\\
|\phantom{..................}|\phantom{.......}\\
\ce{(CHOH)4 ->[Br2 water] (CHOH)4}\\
|\phantom{..................}|\phantom{.......}\\
\ce{\underset{Glucose}{CH2OH}}\phantom{..........}\ce{\underset{Gluconic acid}{CH2OH}}
\end{array}\]