Class 6 Science Separation Of Substances Worksheets
FAQs on Class 6 Science Separation Of Substances Worksheets
1. What kind of Multiple Choice Questions (MCQs) are considered important from CBSE Class 6 Science Chapter 5, Separation of Substances?
For the 2025-26 exams, important MCQs from this chapter typically test your knowledge of specific separation methods. Expect questions where you have to identify the correct technique for a given mixture. For example:
The method used to separate stones from rice is handpicking.
Separating bran from flour is done by sieving.
The process of settling down heavy particles in a liquid is called sedimentation.
Obtaining salt from seawater involves evaporation.
2. Which types of 2 or 3-mark important questions are frequently asked from the chapter Separation of Substances?
Short answer questions often require you to define key terms, give reasons, or differentiate between two methods. Important questions for exams include:
Defining terms like decantation, filtration, and saturated solution.
Explaining why handpicking is a preferred method for separating slightly larger impurities.
Differentiating between winnowing and sieving with suitable examples.
Answering 'why' questions, such as 'Why is filtration better than decantation for separating mud from water?'
3. What are some expected 5-mark long answer questions from Class 6 Science Chapter 5?
Long answer questions (5 marks) usually test your in-depth understanding of a process and often require a labelled diagram. An expected question would be to explain a procedure step-by-step. For instance, a common important question is: 'Explain the process of separating a mixture of sand and salt in water with the help of diagrams.' This would require explaining the sequence of sedimentation, decantation, filtration, and finally, evaporation to recover the salt.
4. A student is given a mixture of muddy water. Which two methods should be used in sequence to obtain clear water, and why is this sequence important?
To get clear water from a muddy mixture, the correct sequence of methods is sedimentation followed by decantation or filtration. The sequence is crucial because:
Step 1: Sedimentation: First, the muddy water must be left undisturbed. This allows the heavier insoluble impurities like sand and soil to settle at the bottom of the container.
Step 2: Decantation/Filtration: After sedimentation, the clear water from the top can be carefully poured out (decantation), or for better results, the entire mixture can be passed through a filter paper (filtration) to remove even finer suspended particles. Skipping sedimentation would quickly clog the filter paper, making filtration inefficient.
5. Why can't winnowing and sieving be used interchangeably to separate mixtures? What is the fundamental difference?
Winnowing and sieving cannot be used interchangeably because they work on different principles. The fundamental difference lies in the property used for separation:
Winnowing separates components based on their weight. It uses wind or blowing air to separate lighter components (like husk) from heavier ones (like grain).
Sieving separates components based on their size. It uses a sieve with pores of a specific size to allow smaller particles to pass through while retaining larger ones.
Therefore, you would use winnowing for a husk-grain mixture (difference in weight) but sieving for a flour-bran mixture (difference in particle size).
6. If you have a mixture of iron filings, sand, and salt, how would you apply more than one separation method to separate all three components?
This is a classic higher-order thinking question that requires a sequence of methods. The correct procedure is:
Step 1: Magnetic Separation. Run a magnet through the mixture. The iron filings will stick to the magnet, separating them from the sand and salt.
Step 2: Filtration. Add water to the remaining mixture of sand and salt and stir. The salt will dissolve, but the sand will not. Pour the mixture through a filter paper. The sand will be left on the filter paper.
Step 3: Evaporation. Heat the salt water (filtrate) that passed through the filter. The water will turn into vapour, leaving the salt behind.
7. How does practising important questions from Chapter 5, Separation of Substances, help in exam preparation for the 2025-26 session?
Practising important questions for this chapter is a key exam strategy. It helps students to:
Identify the most frequently tested concepts, such as the difference between methods and application-based problems.
Understand the types of questions (MCQs, short answer, diagram-based) that are likely to appear in the exam.
Learn how to frame answers correctly as per the CBSE marking scheme, especially for questions that require step-by-step explanations.
Improve time management by practising how to answer different types of questions within the allotted time.
