Definition and Characteristics of Matter - UNSOLVED PRACTICE SET

Q7. Define matter. List two characteristics that distinguish matter from non-matter.

Q8. How does the diffusion of potassium permanganate in water demonstrate the particulate nature of matter?

Q9. Why does a balloon filled with air become tight and firm?

Q10. What is Brownian motion? How does it support the kinetic theory of matter?

Q11. Give two examples from daily life that show matter is made up of tiny particles.

Q12. Why can we smell hot food from a distance more easily than cold food?

Q13. Explain the particulate nature of matter with suitable examples. How do the following observations support this theory:

(a) Dissolution of sugar in water

(b) Compression of gases

(c) Diffusion of gases

Q14. Describe an experiment to demonstrate that matter is made up of tiny particles. Explain your observations and conclusions.

Q15. Discuss the characteristics of particles of matter. How do the properties of particles explain the three states of matter?

Q16. A student performs an experiment to demonstrate the particulate nature of matter:

(a) She takes 50 mL of water in a beaker and marks the level. She then dissolves 10 g of salt in it. The final volume is 52 mL. Calculate the volume occupied by the salt particles and explain why it is less than 10 mL (assuming density of salt = 2.16 g/mL).

(b) She repeats the experiment with 10 g of sugar. The final volume is 56 mL. Calculate the volume occupied by sugar particles and compare with salt. Explain the difference in terms of particle size and packing.

(c) Explain what these experiments demonstrate about the nature of matter.

Q17. In a diffusion experiment, a student places a crystal of potassium permanganate at the bottom of a beaker containing 200 mL of water.

(a) After 1 hour, the purple colour has spread to the top. Calculate the approximate speed of diffusion if the beaker height is 20 cm.

(b) She repeats the experiment with hot water (60°C) and observes that the colour spreads in 20 minutes. Calculate the ratio of diffusion rates and explain why temperature affects diffusion.

(c) Predict what would happen if she used a beaker of mercury instead of water, and explain your reasoning.

Q18. In your school science fair, a student creates a display about the nature of matter.

(a) She demonstrates that 100 mL of water + 100 mL of alcohol gives less than 200 mL of mixture. Calculate the expected volume if the volumes were additive, and explain why the actual volume is less in terms of particle packing.

(b) She then shows that a gas can be compressed much more than a liquid or solid. If a gas occupies 10 L at 1 atm, calculate the approximate volume it would occupy at 100 atm (assuming ideal behaviour), and explain why liquids and solids cannot be compressed similarly.

(c) The student uses the example of a pressure cooker in her kitchen to explain matter. Explain how the pressure cooker demonstrates that matter occupies space and exerts pressure.

(d) A classmate argues that air is not matter because we cannot see it. Design a simple experiment using everyday materials to prove that air is indeed matter and has mass.

(e) In the Indian context, traditional earthen pots (matkas) keep water cool. Explain how this everyday object demonstrates multiple properties of matter — evaporation, latent heat, and the particulate nature of water.