Exploring Mixtures & Their Separation | Class 9 Science Chapter 5 | Part 4 | NCERT Questions

In this video, we solve important NCERT questions from Chapter 5 – Exploring Mixtures and Their Separation for Class 9 Science 2026-27. This session includes detailed explanations of numerical problems, assertion-reason questions, Tyndall effect, distillation, colloids, suspensions, crystallization, separation techniques, and important conceptual questions for exams. 📘 Covered in this video: • NCERT in-text questions • Important conceptual questions • Numericals on concentration • Tyndall effect questions • Distillation & crystallization questions • Colloids, solutions & suspensions • Assertion-reason & case-based questions • Exam-oriented explanations Que: State whether the following statements are True or False. Also, correct the False statements. (i) Salt can be separated from a salt solution by evaporation or distillation. (ii) Distillation can be used for separation of two liquids even when these have the same boiling point. (iii) In paper chromatography, the solvent level should be above the sample spot at the beginning of the experiment. (iv) Evaporation and crystallization are the same processes Que: If 1 mL of a liquid pesticide is mixed with a sufficient amount of water to form 100 mL of a pesticide spray for rice crop, calculate its volume by volume percentage. Que: Which of the following mixtures are correctly classified as homogeneous (Hm) and heterogeneous (Ht)? Choose the correct option. (i) Air — Hm, Milk — Ht, Sugar solution — Hm, Smoke — Hm (ii) Brass — Ht, Fog — Ht, Vinegar — Ht, Muddy water — Hm (iii) Copper sulfate solution — Hm, Salt solution — Hm, Milk — Hm, Bronze — Hm (iv) Muddy water — Ht, Milk — Ht, Blood — Ht, Brass — Hm Que: Choose the correct options, and explain the reason for the correct and incorrect options. Which among the following mixtures show the Tyndall Effect? A mixture of: (a) air and dust particles (b) copper sulfate and water (c) starch and water (d) acetone and water Que: A cake recipe uses dry ingredients, namely 75 g of sugar for 420 g of all-purpose flour and 5 g of sodium hydrogencarbonate. Express the concentration of each component in the mixture using an appropriate method. Que: A brass alloy contains 70% copper by mass. Calculate the quantities of copper and zinc present in 120 g of brass. Que: The label on a cooking oil pack says one litre (910 g). If this oil is mixed with water, will it form a separate layer? If so, which substance will be on top? How will you separate the two layers? Also, draw the diagram of the apparatus used. Que: Assertion (A): Solutions do not exhibit the Tyndall effect. Reason (R): The particles in solutions are larger than 100 nm, so they cannot scatter light. Que: How would you separate the mixtures given in Table 5.3? Mention the reason for choosing your method. If a mixture cannot be separated, explain why. Que: Two miscible liquids, A and B, are present in a mixture. The boiling point of A is 60 °C and the boiling point of B is 90 °C. Suggest a method to separate them. Also, draw a labelled diagram of the method suggested. Que: Blood is an example of a colloidal mixture. (i) What would happen if blood behaved like a true suspension inside the body? (ii) In a blood sample, identify the dispersed phase and the dispersion medium. Que: Compare evaporation, crystallization and distillation. In which situation, would you prefer each of these over the others? Que: Why is distillation an effective method for separating a mixture of water and acetone? Que: Answer the following questions with the help of the data given in Table 5.4. Solubility of various salts (in g per 100 g of water) at different temperatures i) What mass of potassium nitrate would be needed to prepare its saturated solution in 50 g of water at 40 °C? ii) A student makes a saturated solution of potassium chloride in water at 80 °C and leaves the solution to cool at room temperature (25 °C). What would she observe as the solution cools? Explain. iii) What is the effect of a change in temperature on the solubility of salts? Also, compare the changes in the solubility of the four given salts with increasing temperature from 10 °C to 80 °C. Que: Which of the following mixtures can be separated by the technique identified above? Use the data given in Table 5.5. Mixtures: (a) water — acetone (b) water — salt (c) acetone — alcohol (d) sand — salt (e) alcohol — chloroform (f) alcohol — benzene 🔥 Perfect for: Class 9 students preparing for school exams, unit tests, half yearly exams, and annual exams. #Class9Science #Chapter5 #MixturesAndTheirSeparation #NCERTSolutions #Science20262027 #Class9Chemistry #SeparationTechniques #TyndallEffect #Colloid #Suspension #Solution #JSRClasses