6
Question Question 6
How would you confirm that a colourless liquid given to you is pure water?
We can confirm if a colourless liquid is pure water by boiling it. If it boils at 100°C, then its pure. However, if there is an increase or decrease in the boiling point, then we can say that impurities are added to water.
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BRIGHT TUTORIALS
CBSE Class IX | Academic Year 2026-2027
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Science | Chapter 2: Is Matter Around Us PureWeb Content — Quick Reference
Chapter 2: Is Matter Around Us Pure — Quick Reference
Quick Revision Points
- Pure substances: fixed composition (elements + compounds). Mixtures: variable composition
- Solution (< 1 nm, transparent), Colloid (1-100 nm, Tyndall effect), Suspension (> 100 nm, settles)
- Concentration = (mass of solute / mass of solution) × 100
- Separation: evaporation, centrifugation, chromatography, distillation, sublimation, crystallisation, separating funnel
- Elements: metals, non-metals, metalloids. Compounds: fixed ratio, chemical separation
- Tyndall effect: scattering of light by colloidal particles (milk, fog, smoke)
Exam Tips for Chapter 2
- Read the detailed chapter notes for complete coverage of all NCERT topics.
- Practice all NCERT in-text and back exercise questions — they are frequently asked in exams.
- Focus on comparison tables, diagrams, and definitions — these are high-scoring areas.
- For numericals (if applicable), practice at least 20 problems of varying difficulty.
- Refer to the practice question bank (200+ questions) for thorough preparation.
Related Resources
- Detailed Notes: ch02-is-matter-around-us-pure.html
- Practice Questions: 100+ questions with answers in 05-practice-questions/
- Chapter Test: 30-mark test paper in 06-tests/chapter-tests-30marks/
- Formula Sheet: Complete formula reference in 03-teacher-aid/formula-sheet.html