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Separation of Solutions and Mixtures

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Mixtures are separated by exploiting physical differences among their components. Chromatography separates by relative attraction to a moving solvent versus a stationary phase; distillation separates by boiling point; filtration separates by particle size. In chromatography, components that interact less with the paper travel farther.

UNIT 3 TOPIC 3.9 • SEPARATION OF SOLUTIONS AND MIXTURES SEPARATION TOOLS Different tools separate the components of a mixture by exploiting different physical properties. 1 PAPER CHROMATOGRAPHY Separates components by how far each travels up the paper. solvent front separated components starting line solvent WHY IT WORKS Spots more soluble in the mobile phase (solvent) and less attracted to the stationary paper travel farther — set by polarity / IMFs. 2 SIMPLE DISTILLATION Separates components by differences in boiling point (volatility). thermometer condenser water out water in receiving flask boiling mixture WHY IT WORKS The more volatile (lower–boiling) component vaporizes first, then condenses in the water-cooled condenser and collects in the flask. HOW THEY COMPARE PAPER CHROMATOGRAPHY Relies on differences in polarity & intermolecular interactions (IMFs). VS. SIMPLE DISTILLATION Relies on differences in boiling point / volatility (vapor pressure). AP Chemistry · Unit 3 · Properties of Substances & Mixtures
Mixtures separate by physical differences. In paper chromatography, components carried by a solvent travel different distances based on how strongly each is attracted to the paper versus the solvent — the more soluble, less-adsorbed components move farther toward the solvent front.
Chromatography Detective · Open the sandbox →

The trap is misreading a chromatogram — assuming the component that travels farthest is simply 'the most of it,' rather than the one least held by the stationary phase. The distance traveled reflects the balance of attractions, not the amount.

The work

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Lesson
Separating Mixtures ›

Chromatography, distillation, and filtration separate mixtures by attraction, boiling point, and size. The lesson reads a chromatogram from the underlying attractions, then closes with a ten-scenario check.

Skill check · 10 scenarios
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Diagnostic
10-item topic check ›

Ten items spanning the Topic 3.9 misconception: chromatography misread — interpreting travel distance as amount rather than as relative attraction to the phases.

Not started · 10 items · ~15 min
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Targeted Practice
Drill a single misconception ›

Pick one of the failure modes you missed and drill it on its own. The round is adaptive: two correct in a row clears the misconception and moves you to the next.

Take the diagnostic to identify your misconceptions
Diagnostic first