Organic Test-Tube Reaction

C=C in Alkenes

• Add a few drops of bromine water

• Present: orange soln → colourless soln

• Not Present: remains orange

O-H in Primary and Secondary Alcohols

• Warm with acidified K₂Cr₂O₇

• Present: orange soln → green soln

• Not Present: remains orange soln

-CHO in aldehyde using Tollens’ Reagent

• Warm with Tollens’ Reagent

• Present: colourless soln→ silver mirror

• Not Present: Remains colourless soln

-CHO in aldehyde with Fehling’s solution

• Warm with Fehling’s soln

• Present: blue soln → orange-red ppt

• Not Present: remains blue soln

-COOH in carboxylic acid

• Add Na₂CO₃

• Present: effervescence / bubbles

• Not Present: no remains colourless soln

-COCl in acyl chloride

• Add H₂O

• Present: white fumes

• Not Present: remains colourless soln

Halide Ion in haloalkane

• Warm with NaOH

• Add AgNO₃

• Present

  • Colourless → white ppt (Cl^-)

  • Colourless → cream ppt (Br^-)

  • Colourless → yellow ppt (I^-)