Question

Which among the following reagents is used to confirm the presence of carbonyl group in glucose?

Options

• dilute HNO₃

• hot HI

• Br₂ water

• NH₂OH

Answer 1

NH₂OH

Explanation:

\[\begin{array}{cc}
\phantom{......}\ce{CHO}\phantom{............}\ce{CH = N-OH}\phantom{}\\
\phantom{}|\phantom{.................}|\phantom{......}\\
\ce{(CHOH)4 ->[NH2OH] (CHOH)4}\\
\phantom{.}|\phantom{.................}|\phantom{.......}\\
\phantom{..}\ce{\underset{Glucose}{CH2OH}}\phantom{..........}\ce{\underset{Glucoxime}{CH2OH}}\phantom{..}
\end{array}\]

Glucose reacts with NH₂OH to form an oxime which confirms the presence of a carbonyl group in glucose.