Chemistry - Reactions of Ethanal

Blue to Red

colour change when Fehling’s solution reacts with ethanal

Fehling’s Solution

is reduced

Cu²⁺ (blue) → Cu⁺ (red)

Ethanoic Acid

what ethanal is oxidised to

Dilute Sulphuric Acid

added to a test tube with KMnO4 when oxidising ethanal

Acidified KMnO4

added to a test tube with dilute sulphuric acid when oxidising ethanal

Pink to Colourless

colour change when KMnO4 is reduced by ethanal

Acidified KMnO4

is reduced

MnO₄^-  (pink) → Mn²⁺ (colourless)

Tollen’s Reagent

mixture of silver nitrate, dilute sodium hydroxide and dilute ammonia

Silver Mirror Test

used to distinguish between aldehydes and ketones

Silver Mirror

formed when ethanal reacts with Tollen’s reagent

Ketones

not easily oxidised, would give a negative result to these tests