Ncert science solutions class 9 Solutions for Chapter 2 is matter around us pure

How would you confirm that a colourless liquid given to you is pure water?

Which of the following materials fall into the category of “pure substance”?

(a) Ice

(b) Milk

(c) Iron

(d) Hydrochloric acid

(e) Calcium oxide

(f) Mercury

(g) Brick

(e) Wood

(f) Air.

Which of the following will show the “Tyndall effect”?

(a) Salt solution

(b) Milk

(c) Copper sulphate solution

(d) Starch solution.

What is meant by a substance?

List the points of differences between homogeneous and heterogeneous mixtures.

How are sol, solution and suspension different from each other?

What type of mixtures are separated by the technique of crystallization?

Classify the following as physical or chemical changes:

• Cutting of trees

• Melting of butter in a pan

• Rusting of almirah

• Boiling of water to form steam

• Passing of electric current through water and water breaking into hydrogen and oxygen gases.

• Dissolving common salt in water

• Making a fruit salad with raw fruits, and

• Burning of paper and wood

Try segregating the things around you as pure substances and mixtures.