Chromatography
9th Class Chemistry Chapter 19 Notes FBISE
Prepare Class 9 Chemistry Chapter 19 with SLO-based solved exercises, conceptual MCQs, short questions, and long questions based on the latest NBF syllabus.
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Class 9 Chemistry Chapter 19 solved notes on Chromatography cover the principle of chromatography (differential migration between stationary and mobile phases), and paper chromatography in full detail — including the step-by-step procedure, the use of locating agents (e.g., ninhydrin) to reveal invisible spots, reading a chromatogram using the Rf value (Rf = distance travelled by spot ÷ distance travelled by solvent front), and identifying unknown substances by comparing Rf values with known reference samples. Designed for FBISE students, these notes include solved textbook exercises, conceptual MCQs, and exam-focused short/long questions based on the latest 2026-2027 syllabus.
Chapter Overview
Chapter 19, 'Chromatography,' introduces students to one of the most important analytical separation techniques in chemistry. The chapter begins by explaining the fundamental principle of chromatography: all chromatographic methods involve two phases — a stationary phase (which does not move) and a mobile phase (which moves through the stationary phase). The separation of mixture components occurs because different substances have different affinities for the two phases, causing them to migrate at different speeds.
The chapter then focuses on paper chromatography in detail. Students learn the step-by-step procedure: applying the sample as a spot on the baseline of the paper, placing the paper in a suitable solvent (mobile phase), allowing the solvent to travel up the paper by capillary action, and then removing and drying the paper. For colourless compounds, a locating agent such as ninhydrin (for amino acids) or iodine vapour is used to make the separated spots visible. Students also learn how to read a chromatogram by measuring the distances travelled by each spot and by the solvent front.
The key analytical tool in paper chromatography is the Rf (Retardation factor) value, calculated as: Rf = Distance travelled by the spot / Distance travelled by the solvent front. Since the Rf value is characteristic of each substance under identical conditions, an unknown substance can be identified by running it alongside known reference substances and comparing their Rf values. These skills are directly assessed in the practical and theoretical portions of the FBISE Class 9 SLO examinations.
Chapter 19 Notes Material
Use the following study material to prepare Chapter 19 completely.
Download Chapter 19 PDF
You can download the PDF version of Class 9 Chemistry Chapter 19 solved notes for offline study. These notes contain textbook exercises, conceptual short questions, and additional practice items matching the latest FBISE, NBF, and National Curriculum guidelines.