1. Liquid Sample (Methanol, Ethanol, Acetone, Glycerol)

1.1. Physical Character

  • State of aggregation
  • Appearance
  • Color
  • Smell

1.2. Preliminary tests

Experiment Observation Inference
Heat a small portion of the sample in a test tube
  • Sample completely evaporates leaving no residue.
  • A syrapy residue appears at first but ultimately evaporates with a white dense fumes.
  • May be methanol or ethanol or acetone
  • May be glycerol
Treat a small portion of the sample with conc. sulfuric acid and warm gently if necessary.
  • Charring takes place
  • No appreciable change with a slight yellow color
  • May be acetone
  • May be glycerol

1.3. Solubility test in water

Experiment Observation Inference
Shake a small portion of the sample with fresh water in a test tube Sample is soluble in water May be methanol or ethanol or acetone or glycerol

1.4. Acidity of the sample

Experiment Observation Inference

Test a portion of the aqueous solution or suspension with

  • Litmus paper
  • solution of sodium bicarbonate
  • Non acidic to litmus
 May be methanol or ethanol or acetone or glycerol

1.5. Preliminary conclusion

From the experiments of solubility and acidity it appears that the given sample is Methanol, Ethanol, Acetone or Glycerol

1.6. Systematic analysis (For sample soluble in water and non-acidic)

Experiment Observation Inference
Add 2 ml of iodine solution to one or two drops of original sample. Add NaOH soln to it with shaking until the deep brown color or the original solution disappears.
  • A pale yellow ppt.
  • No yellow precipitate or glycerol
  • May be ethanol or acetone
  • May be methanol or glycerol
Add a few drops of of sodium nitroprusside solution to a small portion of the original sample. Shake the mixture with ammonium hydroxide solution
  • A violet red color
  • No violet red color
  • Acetone
  • Ethanol
Add a few drops of original sample to a 2 ml solution of borax and phenolphthalein mixture.
  • Pink color of the solution disappears. It reappears upon warming
  • Pink color remains unchanged
  • May be glycerol
  • May be methanol

1.7. Confirmatory test

1.7.1. For Methanol

Experiment Observation Inference
Warm 1g O.S. with 0.5g Salicylic acid in presence of 10 drops conc. sulfuric acid in dry test tube. Cool and pour in 5 ml. water in a dish.
  • Iodex like smell.
 Methyl alcohol
Drop a 2 inch red hot Cu-wire in 2-3 drops of O.S. in a dry test tube. Pungent odor of formaldehyde Methyl alcohol

1.7.2. For Ethanol/Acetone

Perform iodoform test in
  • sodium hydroxide sol
  • ammonium hydroxide
  • Yellow ppt. of in both medium
  • Yellow ppt of iodoform in NaOH medium
  • Acetone
  • Ethanol

1.7.3. For Glycerol

Heat 1ml. O.S. with small amount of potassium hydrogen sulfate A vapor with pungent Glycerol

1.8. Conclusion

  • Name of the given compound
  • Structure of the given compound