Class: 9 Month: June Worksheet
Subject: Science/Chemistry Chapter: 02 – Is matter around us pure?
(Separation of mixtures )
Section A: Exposition
Each question carries 1 mark:
1
Fill in the blanks:
a .Separating funnel technique is used to separate components which are_________
b. Centrifugation technique is used to separate_______________
c .The process of cooling a hot and concentrate solution of a substance to obtain crystals of the solute is called_____________________
d. A simple distillation technique is used for the mixture if_________________________
e. The method used to separate more than two components of a mixture whose difference in
boiling point is <25°C________________________
f. The process of crystallization is used to_______________________
Each question carries 2 marks:
Match the Column I with column II and select the correct option from the codes given
Below
Column I(Mixture) Column II(Technique used to separate the components
Complete the following table:
MIXTURE TYPE SEPARATION TECHNIQUE PRINCIPLE
2.Sulphur +carbon disulphide
3.Sand +water
4.Pigments of flower
5. Iron pins from sand
6. Ammonium chloride and common salt
7.Dyes in black ink
8. Butter from curd.
9. Sodium chloride from its solution water
10.Mercury and water
11.Sodium chloride and naphthalene
Each question carries one mark
Give an example of each:
4. a. Solid solid homogenous mixture
b .Solid solid heterogenous mixture
c. Solid liquid heterogenous mixture
d. Solid liquid homogenous mixture
e. Liquid liquid homogenous mixture
f. Liquid liquid heterogenous mixture
5. Can we separate a mixture of chloroform and water with the help of a separating funnel? If yes, which will form the lower layer?
6. How will you bring in the following separations:
a.Fine mud particles floating in water
b.Carbon particles present in smoke
Each question carries 2 marks:
7
7. How will you account for the following?
a.A mixture of ammonium chloride and camphor cannot be separated by sublimation.
b.Crystallisation is a better technique than evaporation
8. How will you separate a mixture of sodium chloride and ammonium chloride. Give reason.
Section C: Interpretation & Reasoning
Each question carries 1 mark:
9. A house wife churned full cream with a milk churner.
a. What did she observe after churning the milk ?
b. What could be the possible reason for the observation?
10. State the principle of each of the following methods of separation of mixtures.
a. centrifugation method
b. separation using separating funnel.
Each question carries 2 marks:
11. The below diagram shows separation of salt and ammonium chloride taking place.
a. Which separation technique was used for the separation of the given mixture?
b. What is the underlying principle for this technique?
c. Why can’t we use filtration technique for the separation of this mixture?
d. Suggest the sequence of separation technique you will use for the separation of a mixture of camphor, common salt and sand.
12. Latest research in centrifugation techniques has helped mankind at places like medical laboratories. Justify the statement.
The above diagram shows an activity being performed to separate the colours of ink.
a.After the completion of the activity what do you observe on the filter paper?
b.Why do you observe the colours above on the line while the ink spot was put on the line drawn at the bottom
c.Why did the two colours rise to different heights?
d.What do you infer from the demonstration?
e.What could be the essential conditions to separate any dye using this method?
Section D: Problem Solving
Each question carries 3 marks:
14. Give a flow diagram showing the process of obtaining the gases from air.
15. Show diagrammatically how water is purified in the water work system and list the processes involved.
16. Show schematically how the component of the following mixtures can be separated:
a. Iodine +common salt +nitre
b. Iodine +ammonium chloride +sulphur
c. Nitre .sulphur and carbon
d. Camphor ,common salt and sand
e. Water ,ground nut oil and common salt
f. Chalk powder ,iron fillings and napthalene
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