CBSE Class 9 Science, Is Matter Around Us Pure: Important Topics and Questions

Get the CBSE Class 9th Science chapter, Is Matter Around Us Pure: Important topics & questions to prepare for CBSE Class 9 Science Examination, 2017-2018. This will provide you with a very clear idea about what type of questions are being framed for the exam and from which topics. The pattern in which the question paper is set is quite different from the style in which the course structure is actually defined. Consider the below mentioned terms/questions at the time of preparation.

Check out the important topics to pick from chapter- Is Matter around Us Pure:

• Basic understanding of pure substance and mixture
• Which physical process is being used to separate dissolved sodium chloride from water?
• Name and chemical formula of common salt
• Characteristics exhibited by a pure substance
• How properties of  substance are used to check its purity
• Kinds of mixtures, characteristics of mixtures, and definition of homogenous mixture
• Differences between homogenous and heterogeneous mixtures
• How Iron can be separated from the mixture of iron and sulphur?

Study this table very carefully and try to remember it. Nearly every year questions have been asked in this table.

• Generally mixtures are separated by physical methods and alloy is also a mixture but cannot separate by physical method. Why?
• Constituents of brass
• Fill in the blanks:

          Solid solutions are called _______ and gaseous solutions are called _______

Read the following points carefully:

(i) A solution of sugar in water is a solid in liquid solution. In this solution, sugar is the solute and water is the solvent.

(ii) A solution of iodine in alcohol known as ‘tincture of iodine’ has iodine (solid) as the solute and alcohol (liquid) as the solvent.

(iii) Aerated drinks like soda water etc., are gases in liquid solutions. These contain carbon dioxide (gas) as solute and water (liquid) as solvent.

(iv) Air is a mixture of gas in gas. Air is a homogeneous mixture of a number of gases. Its two main constituents are: oxygen (21%) and nitrogen (78%). The other gases are present in very less quantity.

• List the important characteristics of solution
• Identify solutes and solvents in the following solutions. Also mention the physical state of solutes and solvents.

(a) Sugar in water

(b) Urea in water

(c) Ammonium chloride in water

(d) Ethyl alcohol in water

(e) Carbon Di-Oxide in water (soda water)

• Factors affect the solubility of solvent and solute
• Fish prefer to go in deep waters during day light. Why?
• Air is a mixture not a compound. Why?
• Explanation of saturated, unsaturated, and supersaturated solutions with examples
• What do you mean by suspension? Enlist the properties of suspension?
• Definition and properties of colloids with examples.
• What is emulsion?
• What is the basis of classification of colloid?
• Brownian motion, Electrophoresis, and Tyndall effect
• To make a saturated solution, 36 g of sodium chloride is dissolved in 150 g of water at 293K. Find its concentration at this temperature.
• List all the ways to separate the solid mixture and prepare this as long question
• Define the term chromatography, crystallization, centrifugation, sedimentation, and decantation
• Name the technique to separate

              (i) Butter from curd

              (ii) Salt from sea-water

              (iii) Camphor from salt

Revise the important topics for the chapter Is Matter around Us Pure and then opt for the Important Questions:

Q.  Name the elements are in liquid state at room temperature.

Q. Separate the following as mixture or compound.

(i) Blood

(ii) Common salt

(iii) Sugar

(iv) Brass

Q. Solutions do not exhibit Tyndall effect. Reason

Q. What are the characteristics of mixture?

Q. When we open the cap of an any carbonated beverage (like Pepsi drink), why does excess   of bubbles come out?

Q. What are suspensions? Explain with an example.

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