Separation And Purification
Overview
Most substances in nature come mixed with others, yet chemistry needs pure samples to work with. The art of separation is choosing the right technique for the mixture in front of you, whether that means filtering out a solid, boiling off a solvent, or using boiling-point differences to tease two liquids apart.
In this lesson you will learn the methods of filtration, crystallisation, simple distillation and fractional distillation, when to use each, and how to check whether a substance is pure using its melting and boiling points. These techniques and tests run through the whole of practical chemistry.
Objectives
- [Core] Describe and explain methods of separation and purification using: (a) a suitable solvent (b) filtration (c) crystallisation (d) simple distillation (e) fractional distillation
- [Core] Suggest suitable separation and purification techniques, given information about the substances involved
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Separation And Purification. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which method separates an insoluble solid from a liquid? A. Crystallisation B. Filtration C. Fractional distillation D. Simple distillation Answer: B
- Which method would you use to obtain pure water from salty water? A. Filtration B. Crystallisation C. Simple distillation D. Decanting Answer: C
- Which method best separates a mixture of ethanol and water? A. Filtration B. Fractional distillation C. Crystallisation D. Evaporation Answer: B
- A pure substance has a melting point that is: A. Sharp and fixed B. Spread over a wide range C. Always above 100 degrees Celsius D. Impossible to measure Answer: A
- The presence of an impurity in a solid usually: A. Raises and sharpens the melting point B. Lowers the melting point and spreads it over a range C. Has no effect on the melting point D. Removes the melting point Answer: B
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Recommended Books
Practice Mock Questions
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