UP Board Class 9 Science Chapter 1 Matter In Our Surroundings Multiple Choice Questions

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Matter In Our Surroundings Multiple Choice Questions

Question 1. A diver can cut through water in a swimming pool. The property shown by the matter is

  1. The particles are of very small size
  2. The matter has space between them
  3. The particles are in a solid state
  4. The particles are running here and there, and have no space between them

Answer: 2. The matter has space between them

A diver can cut through water because water is a liquid and has space between the water molecules due to the weak force of attraction among the water molecules.

Question 2. Crystals of KMnO4 in water prove that

  1. KMnO4 is of red color
  2. KMnO4 is acidic
  3. KMnO4 is made up of millions of tiny particles
  4. KMnO4 is a reducing agent

Answer: 3. KMnO4 is made up of millions of tiny particles

When crystals of KMnO4 are added to water, it dissociates into millions of tiny particles, which proves that KMn04 is made up of millions of tiny particles.

Question 3. Honey dissolves slowly in water as a solvent, because

  1. It has a high boiling point
  2. It vaporises easily
  3. It is highly viscous
  4. It has a low melting point

Answer: 3. It is highly viscous

When honey is dissolved in water as a solvent. It dissolves slowly because of its highly viscous nature, i.e. It has high density and a strong force of attraction between the honey molecules.

Question 4. Gases show a faster rate of diffusion because

  1. Of higher boiling point
  2. Of low intermolecular space
  3. Of high melting point
  4. Of large intermolecular space

Answer: 4. Of large intermolecular space

Gases show a faster rate of diffusion because they have weak intermolecular forces between them and move at higher speeds. As a result, these have large intermolecular space between the molecules.

Up Board Class 9 Science Notes For Chapter 1 Matter In Our Surroundings Multiple Choice Questions

Question 5. Which of the following is found in a solid state at room temperature?

  1. Stone
  2. Sand
  3. Mercury
  4. Both (1) and (2)

Answer: 4. Both (1) and (2)

  • Stone and sand are found in a solid state at room temperature because of a strong attractive force among their particles, (i.e. the particles of stone and sand are held together with strong attractive forces).
  • Thus, the intermolecular space among them is very small and these exist as solids, mercury is the only metal which is found in a liquid state at room temperature.

Question 6. The similarity between a liquid and a gas is

  1. Both do not show a definite shape
  2. Both have a definite volume
  3. Both have the same b.p
  4. Both have the same nature

Answer: 1. Both do not show a definite shape

  • Liquids and gases both are considered fluids but due to weak intermolecular force of attraction, gases occupy the shape and volume of a container.
  • Liquids have slightly more force of attraction and thus have definite volume but not definite shape.
  • Hence, we can say that gases have no definite volume and shape, (as they occupy the whole volume and shape of a container) but liquids have definite volume but no definite shape (i.e. they occupy the shape of a container.)

Question 7. For a given mass, identify the correct order of density.

  1. Water < chalk < cotton <air
  2. Chalk < water < cotton < air
  3. Air < cotton < water < chalk
  4. Cotton < air < water < chalk

Answer: 3 and 4

Mass (m) per unit volume (V) is called density

i.e. \(d=\frac{m}{V}\). As intermolecular space (i.e. volume) among the molecules of the given particles is as follows

chalk < water < cotton < air.

Therefore, the order of density will be,

air < cotton < water < chalk

∴ \(\left[d \propto \frac{1}{V}\right]\)

Hence,(3) is the correct option.

Question 8. A gas fills the vessel in which it is kept, because

  1. Of weak intermolecular attractive forces
  2. Of strong intermolecular attractive forces
  3. Of very weak intermolecular repulsive forces
  4. Of fluidity

Answer: 1. Of weak intermolecular attractive forces

A gas fills the vessel in which it is kept because of weak intermolecular attractive forces among the gas molecules. As a result, they can move in the entire vessel and occupy the whole volume of the vessel in which they are kept.

Question 9. A gas can exists the pressure on the walls of the container because

  1. Of high molecular mass
  2. Of high kinetic energy
  3. Of high repulsive forces
  4. Of low intermolecular space

Answer: 2.  Of high kinetic energy

Due to the high kinetic energy (K.E.) possessed by the gas particles, they move with high speed and put pressure on the walls of the container.

Question 10. Any substance is said to be a solid because

  1. Of definite volume and shape
  2. Of high rate of diffusion
  3. Of fluidity
  4. Of the weak force of attraction

Answer: 1. Of definite volume and shape

A substance is said to be a solid because of its definite volume and shape. Since the particles of solids are rigid and have a strong force of attraction, they offer a definite volume and shape to the solids.

Question 11. A solid substance possess

  1. Rigidity fluidity and weak force of attraction
  2. Rigidity fluidity and fixed volume
  3. Rigidity fixed volume and high attractive forces of attraction
  4. Rigidity fixed shape and large intermolecular space between particles

Answer: 3. Rigidity fixed volume and high attractive forces of attraction

  • The solids are rigid and have fixed volume due to the strong force of attraction.
  • They can not flow and, therefore are not considered as fluid. Due to strong forces of attraction, the intermolecular space between their particles is very small.

Question 12. Add a teaspoon full of table salt to water and stir it for some time. On standing, we find that

  1. Water level rises
  2. The water level remains as such
  3. Water level decreases
  4. Water starts boiling

Answer: 2. Water level remains as such

The water level remains as such because table salt dissolves in water completely and occupies the spaces between the particles of water.

Question 13. The same quantity of air and water are compressed with the same pressure, the correct conclusion we find is

  1. Air is compressed more than the water
  2. Water is compressed more than the air
  3. Both are compressed to the same extent
  4. No compression is found in the cases

Answer: 1. Air is compressed more than the water

  • Air will compressed more than water due to the very weak force of attraction among the air molecules as compared to water. As a result, the intermolecular space in air is more than that of water.
  • Hence on applying the same amount of pressure, the air will compressed more than the water.

Question 14. Temperature 200° C equals nearly to

  1. 300 K
  2. 373 K
  3. 473 K
  4. -73 K

Answer: 3.

Celsius scale (° C) and Kelvin scale are related as follows.

Temperature on Kelvin scale

= Temperature on ° C + 273.

Hence, temperature on Kelvin scale = 200 + 273 = 473 K

∴ The option is the correct answer.

Question 15. According to the Kelvin scale, 0° C is equal to

  1. 0 K
  2. 100 K
  3. 273 K
  4. – 273 K

Answer: 3. 273 K

Question 16. A large volume of compressed natural gas (CNG) is available in small cylinders due to its property of

  1. Low density
  2. High compressibility
  3. Easy availability
  4. High inflammability

Answer: 2. High compressibility

Question 17. Which of the following has the highest kinetic energy?

  1. Particles of water at 100° C
  2. Particles of steam at 100° C
  3. Particles of ice at 0° C
  4. Particles of water at 0° C

Answer: 2. Particles of steam at 100° C

Question 18. The density of a substance is defined as

  1. Product of mass and volume
  2. Ratio of mass and volume
  3. Product of mass and temperature
  4. Ratio of mass and temperature

Answer: 2. Ratio of mass and volume

Question 19. The process involving the change of state from solid to gas state is known as

  1. Melting
  2. Sublimation
  3. Fusion
  4. Vapourisation

Answer: 2. Sublimation

Question 20. The temperature at which the solid melts to become a liquid at the atmospheric pressure is known as

  1. Melting point
  2. Boiling point
  3. Freezing point
  4. None of these

Answer: 1. Melting point

Question 21. Which of the following is accompanied by cooling?

  1. Vaporisation
  2. Evaporation
  3. Condensation
  4. Sublimation

Answer: 2. Evaporation

Question 22. Which of the following does not affect the rate of evaporation?

  1. Surface area
  2. Insoluble heavy impurities
  3. Temperature
  4. All of these

Answer: 2. Insoluble heavy impurities

Matter in Our Surroundings Fill In The Blanks.

Question 1. Evaporation of a liquid at room temperature leads to a ____ effect.
Answer:  Cooling

Question 2. At room temperature, the forces of attraction between the particles of solid substances are ____ than those that exist in the gaseous state.
Answer: Stronger

Question 3. The arrangement of particles is less ordered in the state. However, there is no order in the ____ state.
Answer: liquid; gaseous

Question 4. ____ is the change of gaseous state directly to solid state without going through the state.
Answer: Sublimation; liquid

Question 5. The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called ____
Answer: Evaporation

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