Bright Tutorials Bright Tutorials
ICSE Class 7 Chemistry Question 11 of 14

Matter and Its Composition — Question 10

Back to all questions
10
Question

Question 12

Explain the term 'interconversion of matter' - with ice as a starting material. State the term which refers to the conversion of a substance on heating from -

(a) Solid state to liquid state.

(b) liquid state to vapour state.

(c) vapour state to liquid state.

(d) liquid state to solid state.

Answer

Taking ice as a starting material, 'interconversion of matter' can be understood in the following way:

  1. On heating, ice which is in solid state melts and changes into water which is in liquid state.
  2. On further heating, water changes into vapour which is in gaseous state.
  3. When water vapour is allowed to cool, it changes from gaseous state to liquid state forming water.
  4. On cooling water further, it changes to solid state forming ice.

Thus, 'interconversion of matter' involves change of state of matter from one state to another and back to its original state by change in temperature or pressure.

(a) Melting

(b) Vaporisation

(c) Liquefaction or Condensation

(d) Solidification or freezing

ICSE Class VII Chemistry Chapter 1 15 Marks

Matter and Its Composition — Quick Study Guide

Everything around us is made of matter. Matter has mass and occupies space. It exists in three states: solid, liquid, and gas. Each state has unique properties based on how particles are arranged and move.

Key Definitions

  • Matter: Anything that has mass and occupies space
  • Solid: Fixed shape and volume, particles closely packed
  • Liquid: Fixed volume but no fixed shape, particles slide over each other
  • Gas: No fixed shape or volume, particles move freely
  • Diffusion: Spreading of particles from high concentration to low concentration
  • Sublimation: Direct change from solid to gas (e.g., camphor)
  • Latent heat: Heat absorbed during change of state without temperature change

Important Comparisons

Evaporation vs Boiling: Evaporation is a surface phenomenon at all temperatures (slow, no bubbles). Boiling occurs throughout the liquid at a specific temperature (rapid, with bubbles).

Exam Tips

  • Learn all six interconversion processes with examples
  • Practice questions on predicting state at a given temperature
  • Know factors affecting evaporation (4 factors)
  • Understand why pressure cooker cooks faster

Bright Tutorials | ICSE Class VII Chemistry | Chapter 1: Matter and Its Composition | Contact: 9403781999