Chemical tests

Warm with acidified Potassium dichromate (VI).

Orange to Green -

• primary or secondary alcohol
• aldehyde.

Shake with Bromine Water.

Yellow solution decolourised -

• alkene

White precipitate also formed -

• phenol.

Warm with aqueous sodium/potassium hydroxide.

Acidify with dilute nitric acid.

Add aqueous silver nitrate.

White precipitate

• C--Cl

Cream precipitate

• C--Br

Yellow precipitate

• C--I.

Phosphorous (V) Chloride.

Steamy white fumes that turn damp blue litmus paper red

• O--H group in alcohols and carboxylic acids.

2,4 dinitrophenyl hydrazine solution.

Orange precipitate-

• C=O group in aldehydes and ketones.

Boil with Fehling's or Benedict's solution.

Blue solution gives red precipitate:

• aldehyde.

Warm with ammoniacal silver nitrate (tollen's reagent).

Silver mirror

• Aldehyde.

Sodium or Potassium Carbonate, or Hydrocarbonate solution.

Effervescence (fizzing)

• Carboxylic acid.

Add a small piece of Sodium.

Effervescence, Sodium dissolves and a white solid forms.

• Alcohol, Phenol or Carboxylic acid.

Warm with carboxylic acid and a few drops of concentrated sulphuric acid.

Ester smell (glue like).

• Alcohol.

Sodium Nitrite and dilute Hydrochloric acid, followed by an alkaline solution of Phenol in ice cold conditions.

Orange precipitate:

• Aromatic amine.

Iodine in Alkaline solution.

Pale yellow precipitate:

• Methyl, Ketone, Ethanal
• Methyl secondary Alcohol or Ethanol.