CBSE Class 9 Science Exploring Mixtures and Their Separation (Class 9 NCERT New) Quiz 11

1. Which separation technique relies on differences in the boiling points of liquids in a mixture?

A Decantation B Magnetic separation C Distillation D Crystallization

2. A student has a mixture of sand and iron filings. Which separation technique would be most appropriate to separate these two components?

A Filtration B Distillation C Magnetic separation D Chromatography

3. A mixture of salt and water is heated until all the water evaporates. Which separation technique is being used, and what remains after the process?

A Distillation; water remains B Evaporation; salt remains C Filtration; salt remains D Crystallization; water remains

4. Paper chromatography is used to separate the components of a mixture. Which property of the components allows them to be separated using this technique?

A Differences in density B Differences in boiling points C Differences in solubility and how far they travel with the solvent D Differences in magnetic properties

5. A student needs to separate a mixture of alcohol and water. Which technique should be used, and why is simple evaporation not ideal for this separation?

A Filtration; because alcohol is insoluble in water B Distillation; because alcohol and water have different boiling points, allowing selective vaporization C Chromatography; because alcohol and water have different colors D Magnetic separation; because alcohol is magnetic

6. A student has a mixture containing three substances: sand, salt, and iron filings. Design a step-by-step separation plan using appropriate techniques to isolate each component. Which sequence of steps is most logical?

A Filter to remove salt, then use a magnet for iron filings, then evaporate to get sand B Use a magnet to remove iron filings, then dissolve in water and filter to separate sand, then evaporate to recover salt C Distill the mixture to remove sand, then filter to remove iron filings, then evaporate to get salt D Evaporate the mixture to remove salt, then filter to remove iron filings, then use a magnet to separate sand

7. A scientist is analyzing a sample of seawater and needs to obtain pure water from it. She also wants to collect the dissolved salts separately. Considering the properties of the components, which combination of techniques would best achieve both goals, and in what order?

A First filter the seawater, then use chromatography to collect the salts B First use distillation to collect pure water as condensed vapor, then evaporate the remaining solution to collect the salts C First use magnetic separation to remove salts, then evaporate to collect pure water D First use chromatography to separate the water, then filter to collect the salts

8. Two students are given a mixture of blue and red ink dissolved in water. Student A uses paper chromatography, while Student B uses distillation. Which student will successfully separate the ink colors from each other, and why does the other technique fail for this purpose?

A Student B; distillation separates colors based on boiling point differences, while chromatography cannot separate dissolved substances B Student A; chromatography separates components based on their different rates of travel through the medium, while distillation would only separate water from the inks but not the inks from each other C Both students; distillation and chromatography both effectively separate colors in a mixture D Neither student; only filtration can separate colored inks dissolved in water

9. Name a technique used to separate carbon and sulphur.

A Sublimation B Filtration C Distillation D Magnetic

10. Two chemical substances X and Y combine together to form a product P which contains both X and Y. X + Y → P. X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following statements concerning X, Y and P are correct? i. P is a compound. ii. X and Y are compound. iii. X and Y are elements. iv. P has a fixed composition.

A (i), (ii) and (iii) B (i), (ii) and (iv) C (ii), (iii) and (iv) D (i), (iii) and (iv)