Organic compound separation – distillation, extraction, TLC and paper chromatography
ChemistryOrganic ChemistryAges 16–17
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Sign in to playFour familiar techniques in a single simulation. Distillation: heat a liquid mixture and the thermometer holds steady at the boiling point of the more volatile component, while vapor condenses in the condenser and drips into the receiving flask. Extraction: shake the separating funnel so the solute moves from the aqueous layer into the organic solvent layer according to the partition coefficient, then open the stopcock to separate the layers. Thin-layer chromatography: solvent rises up the plate and carries the colored spots at different speeds depending on their polarity, and the simulation instantly calculates the retention factor Rf. Paper chromatography: spot inks, food colorings, leaf pigments or amino acids on a pencil baseline, run a solvent, mark the front and measure each spot with a ruler to calculate Rf and identify the components.
Lesson: Separation and purification methods for organic compounds: distillation, extraction, crystallization, chromatography
What it shows
Every separation method exploits one physical difference between the components of a mixture. Simple distillation separates miscible liquids by boiling point, and the ethanol–water azeotrope limits the purity it can reach. Liquid–liquid extraction relies on a solute distributing itself between two immiscible solvents according to its partition coefficient. Chromatography separates substances by how strongly the stationary phase holds them: a silica plate in TLC, water in the cellulose fibers of paper. The retention factor Rf, measured from the baseline, identifies a substance when compared with references in the same solvent.
How to use
Pick a Method and a Mixture, then press Run. In Distillation, watch where the thermometer levels off; in Extraction, compare hexane with ethyl acetate. In Paper chromatography, choose a sample set and a solvent, press Pause to mark the solvent front, then tap each spot to record its distance and Rf in the table. Compare the unknowns with the reference lanes, and try drawing the baseline in ink or raising the solvent above it.
Parameters you can change
- Method Simple distillation, Liquid–liquid extraction, Thin-layer chromatography, Paper chromatography
- Mixture Ethanol + water, Hexane + toluene, Iodine dissolved in water, Leaf pigments (chlorophyll, carotene)
- Solvent Hexane (nonpolar), Ethyl acetate (moderately polar), Ethanol (strongly polar)
- Animation speed 0.5–3 ×
- Samples spotted on the paper Felt-tip pen inks, Food colorings, Leaf pigments (sun and shade leaves), Amino acids (located with ninhydrin)
- Paper chromatography solvent Water, Ethanol, Petroleum ether + propanone (9 : 1), Butan-1-ol + ethanoic acid + water (4 : 1 : 5)
Questions to explore
- Which method would you choose to remove iodine from water, and which solvent transfers the largest share of it?
- Why do leaf pigments separate into several spots on the TLC plate, and which pigment travels farthest?
- Why is the baseline drawn in pencil and above the solvent level, and how is Rf calculated from it?
Teaching ideas
All guides- Recrystallization Virtual Lab: Purity and Melting PointA recrystallization virtual lab: purify crude benzoic acid, calculate the percentage recovery and test purity by melting point, then try fast cooling.
- Paper Chromatography Virtual Lab: Food Colors and RfA paper chromatography virtual lab: separate candy food colors, measure spots with a ruler, calculate Rf values and identify the dyes from reference lanes.
