Salicylate color test

Determination of salicylates using the occurrence of violet color in the solution

Scientific name: Applying a qualitative reaction of salicylates and iron (III) ions

YouTube

The Home Scientist 023 - Salicylate determination with visual colorimetry, Part I

by TheHomeScientist

What would happen? Aspirin/Salicylic Acid is treated with Ferric Chloride!

by Terry Patamawenu

Ferric Chloride Test

by Joe Smith

Safety

Wear eye protection and lab gloves.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

C7H4O3 2-+ [Fe(H2O)6]3+ → [(C7H4O3)Fe(H2O)4]+ + 2H2O

Step-by-step instruction

  1. Prepare 0.1% solution of iron (III) chloride in water.
  2. Prepare a set of salicylic acid water solutions of various concentrations and pour these solutions into test-tubes.
  3. Prepare a water solution of aspirin in a test-tube.
  4. Add about 1 ml of the iron (III) chloride solution into each test-tube. Fix color change of solutions.

Scientific background

Iron (III) ions form a blue-violet complex with salicylate dianions, and the intensity of the color depends on the concentration of salicylate dianions. With acetylsalicylic acid (aspirin) a pale pink complex with iron (III) is formed. These two reactions are used for detecting salicylate presence and determining the purity of aspirin.

Danger:
Coolness:
Difficulty:

Published on 17 May 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst