CBSE Worksheet Class 9 Chemistry Chapter 1 Matter in Our Surrounding

CBSE Worksheet on Matter in Our Surroundings for class 9 Chemistry chapter 1 introduces you to the fundamental concepts of matter, its states, and properties. This Class 9 Chemistry worksheet is designed to help you strengthen your understanding of the topic through engaging questions and practice exercises.

This worksheet on Matter in Our Surroundings Class 9 covers important points from the chapter and includes answers to guide your learning. Whether you’re revising concepts, preparing for exams, or just exploring the topic, this Matter in Our Surroundings Class 9 worksheet with answers will be your helpful study companion. You can also download the PDF for offline practice.

Get into the Chapter 1 Matter in Our Surroundings worksheet and enhance your grasp of the subject with a focus on clarity and outcomes.

Class 9 Chemistry Chapter 1 Matter in Our Surroundings Overview

Chapter 1 of Class 9 Chemistry Matter in Our Surroundings introduces the fundamental concepts of matter, its properties, and its states. This chapter forms the foundation of Chemistry by explaining how matter behaves under different conditions and its transformations.

Here’s an overview of the key concepts covered in the chapter:

1. Definition of Matter

• Matter is anything that occupies space and has mass.
• Examples: Air, water, plants, animals, etc.
• Matter exists in various forms, such as solids, liquids, and gases, based on its physical state.

2. Characteristics of Particles of Matter

• Particles of matter are very small: They cannot be seen with the naked eye.
• They have spaces between them: The spaces vary based on the state of matter.
• They are in constant motion: The motion depends on temperature and the state of matter.
• They attract each other: The strength of attraction varies between solids, liquids, and gases.

3. States of Matter

Matter exists in three main states:

1. Solid:
   • Particles are tightly packed.
   • Fixed shape and volume.
   • Least compressible and do not flow.
2. Liquid:
   • Particles are less tightly packed than in solids.
   • No fixed shape but a fixed volume.
   • Can flow and are more compressible than solids.
3. Gas:
   • Particles are widely spaced.
   • No fixed shape or volume.
   • Highly compressible and can flow easily.

4. Effect of Temperature on Matter

• Change of State: Matter changes its state when heat is added or removed.
  • Melting: Solid to liquid (e.g., ice to water).
  • Boiling/Evaporation: Liquid to gas (e.g., water to steam).
  • Condensation: Gas to liquid (e.g., steam to water).
  • Freezing: Liquid to solid (e.g., water to ice).
  • Sublimation: Solid to gas without becoming liquid (e.g., camphor).
• Latent Heat:
  • Latent heat of fusion: Heat required to change a solid into a liquid.
  • Latent heat of vaporization: Heat required to change a liquid into a gas.

5. Effect of Pressure on Matter

• Increase in pressure can compress gases and change them into liquids.
• Example: Liquefied Petroleum Gas (LPG) and Compressed Natural Gas (CNG).

6. Diffusion

• Particles of matter can intermix on their own due to their motion.
• Diffusion occurs faster in gases than in liquids and solids.
• Example: The smell of perfume spreading in a room.

7. Kinetic Energy of Particles

• Particles of matter have kinetic energy, which increases with an increase in temperature.
• The higher the temperature, the faster the particles move.

8. Evaporation

• The process of a liquid changing into a gas at any temperature below its boiling point.
• Factors affecting evaporation:
  1. Surface area: Larger surface area increases evaporation.
  2. Temperature: Higher temperature speeds up evaporation.
  3. Humidity: Lower humidity increases evaporation.
  4. Wind speed: Higher wind speed accelerates evaporation.

Matter in Our Surroundings Class 9 Worksheet with Answers

Section A: Fill in the Blanks

1. Matter is anything that has ____ and occupies ____.
2. The process by which a solid directly changes into a gas is called ____.
3. Particles in a ____ state have the highest kinetic energy.
4. The temperature at which a liquid changes into a gas is called its ____.
5. The ____ heat of vaporization is the amount of heat required to change 1 kg of liquid into gas without a temperature change.

Answers to Section A

1. Mass, space
2. Sublimation
3. Gaseous
4. Boiling point
5. Latent

Section B: Multiple-Choice Questions (MCQs)

1. Which of the following processes is an example of sublimation?
   a) Melting of ice
   b) Conversion of camphor to vapors
   c) Freezing of water
   d) Boiling of water
2. Which of these factors increases the rate of evaporation?
   a) Decrease in surface area
   b) Increase in humidity
   c) Increase in temperature
   d) Decrease in wind speed
3. What is the boiling point of water at standard atmospheric pressure?
   a) 0°C
   b) 50°C
   c) 100°C
   d) 212°C
4. In which state of matter are particles arranged most tightly?
   a) Solid
   b) Liquid
   c) Gas
   d) Plasma
5. The process of changing a liquid into a solid is called:
   a) Evaporation
   b) Freezing
   c) Sublimation
   d) Condensation

Answers to Section B

1. b) Conversion of camphor to vapors
2. c) Increase in temperature
3. c) 100°C
4. a) Solid
5. b) Freezing

Section C: Match the Following

Answers to Section C

Section D: Short-Answer Questions

1. Define matter. Give two examples each of solid, liquid, and gas.
2. Explain why gases can be compressed more easily than solids and liquids.
3. Why does evaporation cause cooling?
4. What is the effect of pressure on the state of matter?
5. What is latent heat? Explain its types.

Answers to Section D

1. Matter is anything that occupies space and has mass. Examples:
   • Solid: Ice, Iron
   • Liquid: Water, Milk
   • Gas: Air, Oxygen
2. Gases can be compressed more easily because the particles are widely spaced with large intermolecular spaces, allowing them to be brought closer by applying pressure.
3. During evaporation, particles with higher kinetic energy leave the liquid surface, lowering the average kinetic energy of the remaining particles. This decreases the temperature, causing cooling.
4. Increasing pressure compresses particles, reducing intermolecular spaces. This can change gases into liquids or liquids into solids.
5. Latent heat is the heat absorbed or released during a phase change without changing the temperature.
   • Latent heat of fusion: Heat required to change solid to liquid.
   • Latent heat of vaporization: Heat required to change liquid to gas.

Section E: Long-Answer Questions

1. Describe the factors affecting evaporation.
2. What are the characteristics of particles of matter? Explain with examples.

Answers to Section E

1. The factors affecting evaporation are:
   • Surface Area: Larger surface area increases evaporation.
   • Temperature: Higher temperature increases the kinetic energy of particles, speeding up evaporation.
   • Humidity: Lower humidity increases evaporation as the air can hold more water vapor.
   • Wind Speed: Higher wind speed removes water vapor quickly, increasing the rate of evaporation.
2. The characteristics of particles of matter are:
   • They are very small: Cannot be seen with the naked eye (e.g., sugar dissolving in water).
   • They have spaces between them: Evident when gases mix.
   • They are in constant motion: Evident in diffusion (e.g., perfume spreading in a room).
   • They attract each other: Stronger in solids, weaker in gases.