Question

Write a Fehling solution test for ethanal.

Answer 1

If Fehling’s solution is boiled with ethanal, the deep blue colour of the solution goes away, leaving behind a red Cu₂O precipitate.

\[\begin{array}{cc}
\ce{O}\phantom{..................................}\ce{O}\phantom{......}\\
//\phantom{..................................}//\phantom{........}\\
\ce{\underset{Ethanal}{CH3 - C} + \underset{Fehling’s solution}{2Cu^{++}} + 4OH- ->[\Delta] \underset{Acetic acid}{CH3 - C} + \underset{Red ppt}{Cu2O ↓} + 2H2O}\\
\phantom{...}\backslash\phantom{....................................}\backslash\phantom{...........}\\
\phantom{..}\ce{H}\phantom{...................................}\ce{OH}\phantom{......}
\end{array}\]