Exploring Mixtures and Their Separation- IMPORTANT MCQ TYPE QUESTIONS

1. When two or more different substances are mixed in any proportion such that no chemical reaction takes place, the product so formed is called _________. 

 (A) impure substance

(B) mixture

(C) colloid

(D) suspension

2. 2 g of powdered copper sulphate is added to 20 mL of water and the contents throughly stirred. The products so obtained is called _________.

(A) colloidal solution

(B) heterogeneous solution

(C) homogeneous solution

(D) none of these

3. Which is a homogeneous mixture?

(A) Fruit juice

(B) Mixture of iron and sulphur

(C) Mixture of sand and sugar

(D) Brass

4. Which is a heterogeneous mixture?

(A) Sulphur dissolved in carbon disulphide

(B) Iodine dissolved in carbon tetrachloride

(C) Starch dissolved in water

(D) Common salt solution

5. A homogeneous mixture of two or more substances is called _________.

(A) suspension

(B) solvent

(C) solution

(D) colloidal solution

6. Sugar dissolves in water to form a homogeneous mixture. In this mixture _________ is the solvent..

(A) sugar

(B) water

(C) sugar solution

(D) none of these

7. Sulphur dissolves in carbon disulphide to form a homogeneous mixture

(A) sulphur is the solute

(B) carbon disulphide is the solute

(C) both (A) and (B) are solutes

(D) neither (A) nor (B) is solute.

8. Which one among the following is an example of a solid-solid solution?

(A) A mixture of sugar and sand

(B) Solution of iodine in ethyl alcohol

(C) Solution of acid and water

(D) Brass

9. Which one of the following is an example of a solid-liquid solution?

(A) Tincture of iodine

(B) Molten copper and zinc

(C) Vinegar

(D) Soda water

10. Which one is a liquid-liquid solution?

(A) Ammonium hydroxide  

(B) Dilute sulphuric acid

(C) Fuel mixture of petrol car

(D) Soda water

11. Which one is a liquid-gas solution?

(A) Aerated water

(B) Dilute acetic acid

(C) Tincture of iodine

(D) Glucose solution

12. Bell metal is a solid solution of 80% copper and 20% tin. In bell metal:

(A) tin is the solvent and copper is the solute.

(B) copper is the solvent and tin is the solute.

(C) both copper and tin are the solvents.

(D) both copper and tin are the solutes.

13. A solution in which the particles of the solute are broken down to such a fine state, that they cannot be seen under the most powerful microscope is called _________.

(A) colloidal solution

(B) saturated solution

(C) true solution

(D) none of the above

14. The diameter of the particles in a true solution is:

(A) less than 1 nm.

(B) between 10 nm and 1 nm.

(C) between 1 nm and 100 nm.

(D) more than 100 nm.

15. Which is not a correct statement regarding a true solution?

(A) It is transparent to light.

(B) Its particle size is less than a nanometer.

(C) It is homogeneous in nature.

(D) The particles of solute can be recovered by the process of filtration.

16. When crystals of lead acetate and potassium iodide are grounded in a pestle and mortar no visible reaction takes place. However, when their true solutions in water are mixed, immediately a yellow precipitate of lead iodide is formed. It is because:

(A) water acts as a catalytic agent.

(B) water breaks the particles to molecular level.

(C) a large number of molecules of both the reactants come closer to one another and a chemical reaction takes place.

(D) both (B) and (C).

17. 20% common salt solution means:

(A) 100 g of common salt solution contains 20 g of common salt as solute.

(B) 100 g of water contains 20 g of common salt as solute.

(C) 120 g of common salt solution contains 20 g of common salt as solute.

(D) none of the above.

18. A solution is made by dissolving 25 g of sugar in 175 g of water. The concentration of sugar solution is:

(A) 15%

(B) 14.5%

(C) 12.5%

(D) 13.5%

19. 12% glucose solution is prepared by dissolving 50 g of glucose in water. The amount of water required is:

(A) 360.33 g

(B) 366.67 g

(C) 364.33 g

(D) 367.67 g

20. 20 g of acetic acid is dissolved in 250 mL of water. The concentration of the acid solution is:

 (A) 8%

(B) 8.2%

(C) 9.4%

(D) 7.8% 21. At a given temperature, a solution which cannot dissolve more of the solute is called:

(A) saturated solution

(B) supersaturated solution

(C) true solution

(D) unsaturated solution

22. At a given temperature, a solution which can dissolve more of the solute is called _________.

(A) saturated solution

 (B) true solution

(C) unsaturated solution

(D) supersaturated solution

23. An unsaturated solution of potassium nitrate at 40°C, can be saturated:

(A) by cooling the solution.

(B) by evaporating the solution.

(C) by adding more potassium nitrate.

(D) all of these

24. 21 g potassium nitrate dissolves in 100 g of water at 10°C. The solubility of potassium nitrate is:

(A) 21 g/100 g of water at 10°C

(B) 21 g/121 g of solution at 10°C

(C) 21 g/100 g of water

(D) none of these

25. The solubility of a saturated solution at some known temperature on heating:

(A) increases

(B) decreases

(C) remains same

(D) none of the above

26. When the temperature of a saturated solution is raised it:

(A) becomes super-saturated

(C) remains saturated

(C) remains same

(B) becomes unsaturated

(D) none of the above

27. A saturated solution at 80°C is cooled to 20°C. During the fall in temperature:

(A) the solution remains saturated .

(B) crystals of solute appear at its base.

(C) the solubility of the solute decreases.

(D) all of these

28. The solubility of potassium nitrate is 62 g / 100 g of water at 313 K. The amount of potassium nitrate required to prepare its saturated solution at 313 K in 50g water is:

(A) 31 g

(B) 33 g

(C) 31.5 g

(D) 32.5 g

29. A heterogeneous mixture of insoluble particles of a solute which spreads throughout a solvent is called:

(A) colloidal solution

(B) heterogeneous mixture

(C) suspension

(D) none of these

30. Which is the incorrect statement regarding suspensions?

(A) The solute particles have a tendency to remain suspended in the solvent.

(B) The diameter of the suspended particles is more than 100 nm.

(C) The particles of solute can be filtered out.

(D) The path of light through a suspension is visible.

 Ans: 1. (B)     2. (C)         3. (D)    4. (C)    5. (C)    6. (B)    

 7. (A)       8. (D)     9. (A)    10. (B)   11. (A)    12. (B)      13. (C)  

14. (A)     15. (D)   16. (D)    17. (A)   18. (C)   19. (B)      20. (A)   

21. (A)      22. (C)   23. (D)    24. (A)   25. (A)  26. (B)       27. (D) 

28. (A)   29. (B)       30. (A)

 

Class IX science PWT -1 question paper sample

CHEMISTRY 13 MARKS

Case-Based Questions (QN 1-4) ​4

Rohan was observing his mother making tea. He noticed that when sugar was added to the hot milk, it dissolved quickly even without stirring. He also observed that the aroma of the hot tea spread throughout the room.

1. What characteristic of particles of matter allows sugar to dissolve in milk?

2. What phenomenon is responsible for the aroma of hot tea spreading in the room?

3. Name one factor that affects the rate of this phenomenon.

4. If the tea was cold, would the sugar dissolve faster or slower?

5. Explain why a gas can be easily compressed but a solid cannot.​​​​2

6. Describe an activity to show that particles of matter have spaces between them.​2

7. Convert the following temperatures: 2

a) 300 K to Celsius scale 

b) 50°C to Fahrenheit scale  

8. Explain the relationship between density, mass, and volume. A metal block has a mass of 150 kg and a volume of 0.05 m³. Calculate the density of the metal.​3

Biology 14 MARKS

9. The nucleus of the cell was discovered by-

(a) Robert Hooke    (b)  Robert Cook      

(c) Robert Brown   (d) Lueenhooke        [1]

10. The substance present in cell wall of plant and fungi cells are-

(a) Protein and Lipid respectively            

(b) Cellulose and Chitin respectively

(c)Chitin and Cellulose respectively       

(d) Cellulose and Pepditoglycan respectively​  [1]

11. The plasma membrane of a cell is 

(a) Impermeable         

(b) Permeable   

(c) Semi permeable  

(d) None of these         ​​[1]

12. consists of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:​​​​​​​​1

(a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true but R is not the correct explanation of A.​

(c) A is true but R is false

​(d) A is false but R is true

Assertion: The cell is structural unit of life.

Reason: Cell is smallest unit  capable of performing all the functions necessary for life.

13. Why do cells of multicellular organisms attain various shapes and sizes?                                   [2]

14. Who first proposed cell theory ? Who modified it? State the cell theory statement.                     [3]

15..The diagram of plant cell is given below. Study the structure and answer the question follows 

CBSE Class IX Science syllabus 2022-23

 COURSE STRUCTURE  CLASS IX

(Annual Examination)                                                                                                                

Marks: 80

Unit No.	Unit	Marks
I	Matter - Its Nature and Behaviour	25
II	Organization in the Living World	22
III	Motion, Force and Work	27
IV	Food; Food Production	06
	Total	80
	Internal assessment	20
	Grand Total	100

 

 

 

 

 

Theme: Materials

Unit I: Matter-Nature and Behaviour

Definition of matter; solid, liquid and gas; characteristics - shape, volume, density; change of state- melting (absorption of heat), freezing, evaporation (cooling by evaporation), condensation, sublimation.

Nature of matter: Elements, compounds and mixtures. Heterogeneous and homogenous mixtures, colloids and suspensions. Physical and chemical changes (excluding separating the components of a mixture).

Particle nature and their basic units: Atoms and molecules, Law of Chemical Combination, Chemical formula of common compounds, Atomic and molecular masses.

Structure of atoms: Electrons, protons and neutrons, Valency, Atomic Number and Mass Number, Isotopes and Isobars.

Theme: The World of the Living

Unit II: Organization in the Living World

Cell - Basic Unit of life : Cell as a basic unit of life; prokaryotic and eukaryotic cells, multicellular organisms; cell membrane and cell wall, cell organelles and cell inclusions; chloroplast, mitochondria, vacuoles, endoplasmic reticulum, Golgi apparatus; nucleus, chromosomes - basic structure, number.

Tissues, Organs, Organ System, Organism:

 

Structure and functions of animal and plant tissues (only four types of tissues in animals; Meristematic and Permanent tissues in plants).

Theme: Moving Things, People and Ideas Unit III: Motion, Force and Work

Motion: Distance and displacement, velocity; uniform and non-uniform motion along a straight line; acceleration, distance-time and velocity-time graphs for uniform motion and uniformly accelerated motion, elementary idea of uniform circular motion.

Force and Newton’s laws : Force and Motion, Newton’s Laws of Motion, Action and Reaction forces, Inertia of a body, Inertia and mass, Momentum, Force and Acceleration.

Gravitation: Gravitation; Universal Law of Gravitation, Force of Gravitation of the earth (gravity), Acceleration due to Gravity; Mass and Weight; Free fall.

Floatation: Thrust and Pressure. Archimedes’ Principle; Buoyancy.

Work, Energy and Power: Work done by a Force, Energy, power; Kinetic and Potential energy; Law of conservation of energy (excluding commercial unit of Energy).

Sound: Nature of sound and its propagation in various media, speed of sound, range of hearing in humans; ultrasound; reflection of sound; echo.

 Theme: Food

Unit IV: Food Production

Plant and animal breeding and selection for quality improvement and management; Use of fertilizers and manures; Protection from pests and diseases; Organic farming.

Note for the Teachers:

 

1.     The chapter Natural Resources (NCERT Chapter 14) will not be assessed in the year-end examination. However, learners may be assigned to read this chapter and encouraged to prepare a brief write up on any concept of this chapter in their Portfolio. This may be for Internal Assessment and credit may be given for Periodic Assessment/Portfolio.

2.     The NCERT text books present information in boxes across the book. These  help students to get conceptual clarity. However, the information in these boxes would not be assessed in the year-end examination.

PRACTICALS

Practicals should be conducted alongside the concepts taught in theory classes

(LIST OF EXPERIMENTS)

1.    Preparation of:               Unit-I

 

a)     a) true solution of common salt, sugar and alum 

      b)  a suspension of soil, chalk powder and fine sand in water

      c)       a colloidal solution of starch in water and egg albumin/milk in water and distinguish between these on the basis of

        ·       transparency

        ·       filtration criterion

        ·       stability

2.        Preparation     of      Unit-I

           A mixture   b)       A compound using iron filings and sulphur powder and distinguishing between these on the basis of:  

(i)       appearance, i.e., homogeneity and heterogeneity

(ii)     behaviour towards a magnet

(iii)    behaviour towards carbon disulphide as a solvent

(iv)   effect of heat

3.               Perform the following reactions and classify them as physical or chemical changes: Unit-I

a)         Iron with copper sulphate solution in water

b)         Burning of magnesium ribbon in air

c)         Zinc with dilute sulphuric acid

d)         Heating of copper sulphate crystals

e)         Sodium sulphate with barium chloride in the form of their solutions in water

4.               Preparation of stained temporary mounts of (a) onion peel, (b) human cheek cells & to record observations and draw their labeled diagrams. Unit-II

5.               Identification of Parenchyma, Collenchyma and Sclerenchyma tissues in plants, striped, smooth and cardiac muscle fibers and nerve cells in animals, from prepared slides. Draw their labeled diagrams. Unit-II

6.               Determination of the melting point of ice and the boiling point of water. Unit-I

7.               Verification of the Laws of reflection of sound. Unit-III

 8.               Determination of the density of solid (denser than water) by using a spring balance and a measuring cylinder. Unit-III

9.               Establishing the relation between the loss in weight of a solid when fully immersed in Unit-III

a)      Tap water 

        b)      Strongly salty water with the weight of water displaced by it by taking at least two different solids.

    10.           Determination of the speed of a pulse propagated through a stretched string/slinky (helical spring). Unit-III

11.           Verification of the law of conservation of mass in a chemical reaction. Unit-III