CBSE Class 9 Chemistry Is Matter Around Us Pure Worksheet Set A

Read and download free pdf of CBSE Class 9 Chemistry Is Matter Around Us Pure Worksheet Set A. Students and teachers of Class 9 Chemistry can get free printable Worksheets for Class 9 Chemistry in PDF format prepared as per the latest syllabus and examination pattern in your schools. Standard 9 students should practice questions and answers given here for Chemistry in Grade 9 which will help them to improve your knowledge of all important chapters and its topics. Students should also download free pdf of Class 9 Chemistry Worksheets prepared by school teachers as per the latest NCERT, CBSE, KVS books and syllabus issued this academic year and solve important problems provided here with solutions on daily basis to get more score in school exams and tests

Is Matter Around Us Pure Class 9 Chemistry Worksheet Pdf

Class 9 Chemistry students should refer to the following printable worksheet in Pdf for Is Matter Around Us Pure in standard 9. This test paper with questions and answers for Grade 9 Chemistry will be very useful for exams and help you to score good marks

Class 9 Chemistry Worksheet for Is Matter Around Us Pure

 

Very Short Answer Type Questions

Question. Name the types of mixtures.
Answer : Homogeneous mixture and heterogeneous mixture.

Question. Define dispersion medium.
Answer :  It is the component which is present in excess and acts as a medium in which colloidal particles are dispersed.

Question. A colloid which have liquid as dispersed phase and solid as dispersion medium called-
Answer : Gel.

Question. The component of solution that is present in smaller proportion
Answer : Solute.

Question. Name a metal which is liquid at room temperature.
Answer : Mercury.

Question. An element made up of only one type of—
Answer : Atom.

Question : How would you confirm that a colorless liquid given to you is pure water?
Answer : 
If the given colorless liquid boils at 100°C sharp, it is pure water, otherwise not.

Question: Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water
Answer : Sea water, air and soda water: Homogeneous mixture Coal, Soil: Heterogeneous solution.

Short / Long Answer Type Questions

Question. (i) State the principle of the process of centrifugation.
(ii) List any three applications of centrifugation.
Answer :
 (i) Centrifugation is the process of separating suspended particles from a liquid like colloids by churning the liquid at a high speed. The principle is that denser particles are forced to the bottom and lighter stay at the top when spun rapidly.
(ii) Applications of centrifugation :
(a) Used in dairies and homes to separate cream from milk or butter from cream.
(b) Used in washing machines to squeeze out water from clothes.
(c) Used in laboratories to separate colloidal particles from their solutions.
(d) Used in diagnostic labs for blood and urine test.

Question. Why is water considered as compound?
Answer :  Water is considered as compound because :
(i) Water is composed of two elements : hydrogen and oxygen.
(ii) The ratio of hydrogen and oxygen by mass in any sample of pure water is the same.
(iii) The properties of water are different from its constituent elements : hydrogen and oxygen.
(iv) Water can be decomposed by chemical means only


Question. Write characteristics of compounds.
Answer : Characteristics of compounds :
(i) Compounds are the substances formed by chemical combination of two or more elements.
(ii) The constituent elements are present in a fixed ratio.
(iii) A chemical reaction takes place during the  formation of a compound.
(iv) Properties of a compound are different to those of its elements.
(v) Constituent elements cannot be separated by physical processes.

Question : Name the technique to separate
(i) Butter from curd
(ii) Salt from sea water
(iii) Camphor from salt
Answer :
(i) By using centrifugation method, butter can be separated from curd.
(ii) By using evaporation method, salt from sea water can be separated .
Water vaporises on evaporation leaving behind the salt.
(iii) Camphor from salt can be separated by sublimation method. On subliming camphor will be converted into vapour leaving behind the salt.

Question : Classify the following as chemical or physical changes
(a) Cutting of trees,
(b) Melting of butter in a pan,
(c) Rusting of almirah,
(d) Boiling of water to form steam,
(e) Passing of electric current, through water and the water breaking down into hydrogen and oxygen gases,
(f) Dissolving common salt in water,
(g) Making a fruit salad with raw fruits, and
(h) Burning of paper and wood
Answer :
Physical Change :
Cutting of trees
Melting of butter in a pan
Boiling of water to form steam
Dissolving common salt in water
Making a fruit salad with raw fruits
Chemical Change :
Rusting of almirah.
Passing of electric current, through water and the water breaking down into hydrogen and oxygen gases.
Burning of paper and wood.

Question : Write the steps you would use for making tea. Use the words solution, solvent,solute, dissolve, soluble, insoluble, filtrate and residue.
Answer :
Method of preparation of tea
(i) Take some water (solvent) in a pan and heat it.
(ii) Add some sugar (solute) and boil to dissolve the sugar completely the obtained homogeneous mixture is called solution.
(iii) Add tea leaves (or tea) in the solution and boil the mixture.
(iv) Now add milk and boil again.
(v) Filter the mixture through the tea stainer and collect the filtrate or soluble substances, i.e., tea in a cup. The insoluble tea leaves left behind as residue in the 8 trainer.

Question : Explain the following giving examples.
(a) Saturated solution
(b) Pure substance
(c) Colloid
(d) Suspension
Answer :
(a) Saturated solution: A solution in which no more amount of solute can be dissolved at a particular temperature is called saturated solution.
Example: when sugar is dissolved repeatedly in a given amount of water, a condition is reached at which further dissolution of sugar is not possible in that amount of water at room temperature.
(b) Pure substance: A substance made up of single type of particles (atoms and/or molecules) is called pure substance. All elements and compounds are said to be pure, Example: water, sugar etc.
(c) Colloid:A heterogeneous mixture in which the solute particle size is too small to be seen with the naked eye, but is big enough to scatter light is known as Colloid. There are two phases in colloidal solution Dispersed phase: solute particles are said to be dispersed phase Dispersion medium: the medium in which solute particles are spread is called the dispersion medium.
Example: Milk, clouds etc., are the example of colloid.
(d) Suspension: A suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium. Particles of suspension are visible to the naked eye.
Example: Mixture of sand, Water and Muddy water etc.

Question : 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
Answer : Elements : Sodium, silver, tin and silicon
Compounds : Calcium carbonate, methane, and carbon dioxide Mixtures : Soil, sugar solution, coal, air, soap and blood.

 

Q.1 Two liquids ‘A’ and ‘B’ are miscible with each other at room temperature. Which separation technique will you apply to separate the mixture of ’A’ and ‘B’ if the difference in their boiling point is 27 deg C?

Q.2 Rain water stored in a tank contains sand grains, unfiltrable clay particles, calcium carbonate, salt, pieces of paper and some air bubbles. Select from amongst these one example each of a solvent, a solute, a colloid and a suspension.

Q.3 Suggest separation technique(s) one would need to employ to separate the following mixtures:

(a) Mercury and Water

(b) Potassium Chloride and ammonium chloride

(c) Common salt, water and sand

(d) Kerosene oil, water and salt

Q.4 Give some examples of Tyndall effect observed in your surrounding

Q5: differentiate between:

(a) true solution & a colloid

(b) metals & non-metals

(c) compound & mixtures

(d) physical & chemical changes.

Q.6: 0.5 g of salt is dissolved in 25g of water. Calculate the percentage amount of the salt in the solution.

Q.7: During an experiment the students were asked to prepare a 10% (Mass/Mass) solution of sugar in water. Ramesh dissolved 10g of sugar in 100g of water while Sarika prepared it by dissolving 10g of sugar in water to make 100g of the solution.

(a) Are the two solutions of the same concentration?

(b) Compare the mass% of the two solutions.

Q.8: Explain why filter paper cannot be used to separate colloids?

Q.9: A compound is regarded as a pure substance while the mixture is not. Assign reason.

Q.10: How can a saturated solution be made unsaturated ?

Q.11: Colloidal solutions show Tyndall effect but true solutions do not. Discuss

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