Organic Chemistry – Some Basic Principles and Techniques

Chemistry · Class 11

Simulation · Chemistry · Class 11

Steam distillation boils below 100 °C

"Steam distillation boils below 100 °C" is a free, interactive Class 11 Chemistry simulation for NEET and JEE, built on the NCERT section "Methods of purification" in Organic Chemistry – Some Basic Principles and Techniques. Vapour-pressure curves of water and an immiscible organic liquid add up; the mixture boils where the sum meets atmospheric pressure, below 373 K, compared with simple and fractional distillation. NEET has asked about this idea 3 times in 10 years of papers. JEE Main asked 91 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).

From the lesson Methods of purification in Organic Chemistry – Some Basic Principles and Techniques. Change the values and watch what happens.

Steam distillation boils below 100 °CChemistry · Class 11

What it shows

NCERT § "Methods of Purification of Organic Compounds"

Vapour-pressure curves of water and an immiscible organic liquid add up; the mixture boils where the sum meets atmospheric pressure, below 373 K, compared with simple and fractional distillation.

Controls

3 to try

  • Segmentedcompound aniline / o-nitrophenol / p-nitrophenol
  • Slidertemperature 300–400 K
  • Sliderexternal pressure 0.2–1 atm

Try this

Find the boiling temperature of the aniline–water mixture at 1 atm (~371.5 K), and the nitrophenol isomer that steam-distils (ortho).

Common mistake

Simple distillation for close-boiling liquids; steam distillation boils at 373 K.

In NEET

10 years of papers

Asked 3 times in 10 years of NEET.

See the past questions: Hydrogen Bonding, Organic Chemistry - Some Basic Principles and Techniques (chapter)

In JEE Main

42 shifts analysed

91 questions from Organic Chemistry – Some Basic Principles and Techniques across the 42 JEE Main shifts Lumi has analysed (2017–2026).

See the past questions

The idea behind it

NCERT § "Methods of Purification of Organic Compounds"

  • Sublimation separates a solid that passes directly into vapour on heating from non-sublimable impurities.
  • Crystallisation relies on the compound being much more soluble in a hot solvent than in the cold one; impurities stay in solution. Repeated crystallisation removes impurities of similar solubility.
  • Simple distillation separates liquids with large boiling point differences, or a volatile liquid from non-volatile impurities.
  • Fractional distillation uses a fractionating column to separate liquids whose boiling points are close; it is used to separate crude oil fractions.
  • Distillation under reduced pressure lets liquids that decompose at or below their normal boiling point boil at a lower temperature; glycerol is recovered from spent-lye this way in soap manufacture.
  • Steam distillation purifies substances that are volatile in steam and immiscible with water, such as aniline; the mixture boils when the sum of the vapour pressures of water and the compound equals atmospheric pressure, below 373 K.
  • Differential extraction shakes an aqueous solution with an organic solvent in which the compound is more soluble and which does not mix with water; the layers are separated in a separating funnel.
  • Chromatography separates components by their different affinities for a stationary phase and a moving (mobile) phase.
  • Adsorption chromatography uses a solid adsorbent such as silica gel or alumina, in column chromatography or thin layer chromatography (TLC); partition chromatography, as in paper chromatography, uses water held in the paper as the stationary phase.
  • Retardation factor Rf = distance moved by the substance from the baseline / distance moved by the solvent front; colourless spots are located under UV light, with iodine vapour or with a reagent such as ninhydrin for amino acids.

Questions

5 answers

What does the "Steam distillation boils below 100 °C" simulation show?
Vapour-pressure curves of water and an immiscible organic liquid add up; the mixture boils where the sum meets atmospheric pressure, below 373 K, compared with simple and fractional distillation.
What mistake does the "Steam distillation boils below 100 °C" simulation fix?
A common mistake it clears up: simple distillation for close-boiling liquids; steam distillation boils at 373 K.
Has NEET asked about this idea?
Yes. NEET has asked about this idea 3 times in 10 years of papers.
Does JEE Main ask questions from Organic Chemistry – Some Basic Principles and Techniques?
Yes. JEE Main asked 91 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
Is this simulation free?
Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Methods of purification" in Organic Chemistry – Some Basic Principles and Techniques (Class 11 Chemistry).

Embed this simulation

Free, with a link back

Teaching this idea? Put the simulation on your own page or LMS with this code.