a) Write the chemical equation for the reaction involved in the Cannizzaro reaction.
b) Draw the structure of the semicarbazone of ethanal.
c) Why is the pKₐ of F–CH₂–COOH lower than that of Cl–CH₂–COOH?
d) Write the product of the following reaction:
e) How can you distinguish between propanal and propanone?
b) Draw the structure of the semicarbazone of ethanal.
c) Why is the pKₐ of F–CH₂–COOH lower than that of Cl–CH₂–COOH?
d) Write the product of the following reaction:
e) How can you distinguish between propanal and propanone?
Solution
(a)
(b) Ethanal + semicarbazide, −HO:
(c) Fluorine is more electronegative than chlorine: its −I pull stabilises FCHCOO more → the acid is stronger → \textbf{lower pK}.
(d) DIBAL-H reduces only the nitrile to the aldehyde:
(e) Tollens' reagent: propanal → silver mirror; propanone → none.
(b) Ethanal + semicarbazide, −HO:
(c) Fluorine is more electronegative than chlorine: its −I pull stabilises FCHCOO more → the acid is stronger → \textbf{lower pK}.
(d) DIBAL-H reduces only the nitrile to the aldehyde:
(e) Tollens' reagent: propanal → silver mirror; propanone → none.
CBSE Class 12 Board · 2016 · Delhi · Subjective