Mrs. Johnson, a high school chemistry teacher, explains the difference between pure substances and mixtures to her class. She tells pure substances and mixtures are two fundamental categories of matter. Pure substances have a uniform and definite composition, consisting of only one type of particle. They can be further classified into elements and compounds. She demonstrates with water (H₂O) and sodium chloride (NaCl), highlighting that compounds have a uniform and definite composition. She shows copper (Cu) as an example of an element, which cannot be broken down into simpler substances. Moving to mixtures, she uses saltwater to illustrate how mixtures consist of two or more substances physically combined, allowing for variable compositions. She then engages students in creating their own mixtures and discussing separation techniques like filtration and evaporation.

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Pure and Impure Substances in Chemistry, Definition of Mixture in Chemistry, Definition and Properties of Colloids | PadhAiPro

Question

CASE_STUDIESPure and Impure Substances in ChemistryDefinition of Mixture in ChemistryDefinition and Properties of Colloids4 sub-questions

Distinguish among true solution, suspension and colloid in a tabular form under the following heads:

Definition and Properties of Solutions

Concentration of a Solution

What is meant by concentration of a solution? How will you prepare a 10% solution of glucose in water?

Draw a neat and labelled diagram of the apparatus used to separate components of blue-black ink. Name the process and state the principle involved.

Identify the physical and chemical changes from the following:

Rohit mixed starch with water, boiled the mixture well and stirred it. He observed that -

The colour of sodium chloride and ammonium chloride respectively is-