Formaldehyde can be distinguished from acetaldehyde by the use of :
Schiff's reagent
Tollen's reagent
Alkali
Fehling's solution
Formaldehyde and acetaldehyde can be distinguished by iodoform test.
? Iodoform test -
- Methyl ketones react with iodine and potassium hydroxide to give yellow precipitate.
? Acetaldehyde vs Formaldehyde -
-Acetaldehyde reacts with iodine and KOH to give sodium salt of carboxylic acid.
CH3CHO + 4NaOH + 2I2 --> CH3I + HCOONa + 3NaI + 3H2O
- Formaldehyde doesn't give iodoform test.
HCHO + NaOH + I2 --> NO REACTION