IS MATTER AROUND US PURE? 9

       Practice Paper

Subject Chemistry (2020)

 CH-2  Is matter around us pure? 

Class IX

I. Very short answer type questions:

1. What do you mean by pure substance?
2. What is an element?
3. What are the four types of elements?
4. What is a mixture? What are its various types?
5. Name two types of mixture.
6. What is a compound?
7. Define solution. 
8. Define solvent.
9. Define true solutions.
10. What is a saturated solution?
11. What is the unsaturated solution?
12. Define solubility.
13. Write the name of two methods to separate different gases from the air.
14. What are alloys?
15. Write the name of the elements of the brass.
16. Define crystallization.
17. Write the name of two elements that are liquid at room temperature.
18. What are metalloids?

II. Short answer type questions:

1. Define solution, solute, and solvent?
2. Write the name of solute and solvent in the following mixture:
   (i) A solution of sugar in water.
   (ii) A solution of iodine and alcohol
   (iii) Aerated drinks like soda water
3. Define homogeneous and heterogeneous mixture.
4. What is a colloidal solution? What are its various properties?
5. What is the Tyndall effect? Which kinds of solutions show it? 
6. Write a method to separate a mixture of salt and ammonium chloride?
7. Define solubility. Write the factors on which solubility depends.
8. How can we separate a mixture of salt and ammonium chloride? 
9. Write two examples where the crystallization technique is better than evaporation.
10. Write the differences between a physical and a chemical change.
11. The interconversion of states is a physical change, why?

III. Long answer type questions:

1. What is a suspension? What are the properties of suspension?
2. A solution contains 60g of NaCl in 400g of water. Calculate the concentration in terms of mass by the mass percentage of the solution.
3. What is centrifugation? Where it is used?
4. What is chromatography? What are its various applications and underline the basic principle involved?
5. What is crystallization? Where is it used? Why is this better than a simple evaporation technique?
6. Define distillation and fractional distillation? What is the basic property that separates the two methods? 
7. What are the properties of a solution?
8. What are the differences between saturated and unsaturated solutions?
9. What do you mean by the concentration of the solution? Write an expression of the concentration of a solution.
10. What are the dispersed phase and dispersed medium in the colloidal solution?
11. How we can obtain coloured component (dye) from blue-black ink? How can we separate cream from milk?
12. Write three applications of the centrifugation method?
13. What is the principle of separation of immiscible liquids? How can we separate a mixture of two immiscible liquids? Writes its applications.
14. Define chromatography. Write its applications.
15. How we can obtain different gases from the air?
16. Explain with an example where both physical and chemical changes take place. 
17. Write five properties of metal and non-metal.
18. Write five differences between the compound and mixture.
19. How we can obtain pure copper sulphate from an impure sample?
20. What do you mean by the concentration of the solution?
21. Write the two expressions of the concentration of a solution.
22. Write the differences between a physical and a chemical change.
23.  A solution contains 40 g of common salt in 320 g of water. Calculate the concentration in terms of mass by the mass percentage of the solution.

NCERT QUESTIONS:

1. What is meant by a pure substance? 
2. List the points of differences between homogeneous and heterogeneous mixtures.
3. Differentiate between homogeneous and heterogeneous mixtures with examples.
4. How are sol, solution, and suspension different from each other? 
5. To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.
6. How will you separate a mixture containing kerosene and petrol (difference in their boiling points is more than 25ºC), which are miscible with each other? 
7. Name the technique to separate: (i) butter from curd, (ii) salt from sea-water, (iii) camphor from salt. 
8. What type of mixtures are separated by the technique of crystallization?
9. Classify the following as chemical or physical 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 the water breaking down into hydrogen and oxygen gases, 
   • dissolving common salt in water, 
   • making a fruit salad with raw fruits, and 
   • burning of paper and wood. 
10. Try segregating the things around you as pure substances or mixtures.
11. Which separation techniques will you apply for the separation of the following? 
    (a) Sodium chloride from its solution in water. 
    (b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride. 
    (c) Small pieces of metal in the engine oil of a car. 
    (d) Different pigments from an extract of flower petals. 
    (e) Butter from curd. 
    (f) Oil from water. 
    (g) Tea leaves from tea. 
    (h) Iron pins from sand. 
    (i) Wheat grains from husk. 
    (j) Fine mud particles suspended in water. 
12. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
13. (a) What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K? 
    (b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain. 
    (c) Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature? 
    (d) What is the effect of change of temperature on the solubility of a salt?
14. Explain the following giving examples. 
    (a) saturated solution 
    (b) pure substance 
    (c) colloid 
    (d) suspension 
15. Classify each of the following as a homogeneous or heterogeneous mixture. soda water, wood, air, soil, vinegar, filtered tea. 
16. How would you confirm that a colourless liquid given to you is pure water?
17. Which of the following materials fall in the category of a “pure substance”? (a) Ice (b) Milk (c) Iron 
    (d) Hydrochloric acid (e) Calcium oxide 
    (f) Mercury (g) Brick (h) Wood (i) Air. 
18. Identify the solutions among the following mixtures. 
    (a) Soil (b) Seawater (c) Air (d) Coal (e) Soda water. 
19. Which of the following will show the “Tyndall effect”? 
    (a) Salt solution (b) Milk (c) Copper sulphate solution (d) Starch solution.
20. Classify the following into elements, compounds and mixtures.
    (a) Sodium (b) Soil (c) Sugar solution 
    (d) Silver   (e) Calcium carbonate (f) Tin 
    (g) Silicon  (h) Coal (i) Air (j) Soap (k) Methane 
    (l) Carbon dioxide (m) Blood.
21. Which of the following are chemical changes?
    (a) Growth of a plant (b) Rusting of iron (c) Mixing of iron filings and sand
    (d) Cooking of food (e) Digestion of food (f) Freezing of water (g) Burning of a candle.

CHAPTER 1 - MATTER IN OUR SURROUNDINGS	☛ QUESTION WITH SOLUTIONS
CHAPTER 2 - IS MATTER AROUND US PURE?	☛QUESTION WITH SOLUTIONS
CHAPTER 3 - ATOMS AND MOLECULES	☛ QUESTION WITH SOLUTIONS
CHAPTER 4 - STRUCTURE OF ATOM	☛   QUESTION WITH SOLUTIONS
CHAPTER 5 -  THE FUNDAMENTAL UNIT OF LIFE
CHAPTER 6 -  TISSUE
CHAPTER 7 -   DIVERSITY IN LIVING ORGANISM
CHAPTER 8 -  MOTION	☛ QUESTION WITH SOLUTIONS
CHAPTER 9 -  FORCE AND LAW OF MOTION	☛  QUESTION WITH SOLUTIONS
CHAPTER 10 - GRAVITATION	☛ QUESTION WITH SOLUTIONS
CHAPTER 11 -  WORK AND ENERGY
CHAPTER 12 -  SOUND
CHAPTER 13-  WHY DO WE FALL ILL
CHAPTER 14 - NATURAL RESOURCES
CHAPTER 15 - IMPROVEMENT OF FOOD RESOURCES