Question

What is Fehling’s reagent? What would you observe on heating formalin with Fehling’s reagent in a test tube?

Answer 1

Fehling's reagent is and aqueous solution Copper (II) Sulphate, which in normal conditions is deep blue in colour. It can be used to test the presence of an aldehyde group in a compound, such as formaldehyde (HCHO, who's aqueous solution is also called formalin).

When Fehling's reagent is heated with formalin, a brick red precipitate is formed.

Answer 2

"Answer:

Fehling's solution is a mixture of alkaline solution of copper(II) sulphate (CuSO4​​) containing sodium potassium tartrate (Rochelle salt).

It can be used to test the presence of an aldehyde group in a compound, such as formaldehyde (HCHO). When Fehling's reagent is heated with formalin, a brick red precipitate is formed and settles on the bottom."