Note:

IGCSE Chemistry Notes /States of matter/ 2026-2027-2028 Exams Free Preview

Syllabus Content:

Core:

1.1 Solids, liquids and gases

Core

1. State the distinguishing properties of solids, liquids and gases
2. Describe the structures of solids, liquids and gases in terms of particle separation, arrangement and motion
3. Describe changes of state in terms of melting, boiling, evaporating, freezing and condensing
4. Describe the effects of temperature and pressure on the volume of a gas

Supplement

1. Explain changes of state in terms of kinetic particle theory, including the interpretation of heating and cooling curves
2. Explain, in terms of kinetic particle theory, the effects of temperature and pressure on the volume of a gas

1.2 Diffusion

Core

1. Describe and explain diffusion in terms of kinetic particle theory Supplement
2. Describe and explain the effect of relative molecular mass on the rate of diffusion of gases

Here  are free summary notes for all :

1.1 Solids, Liquids, and Gases

1. Distinguishing Properties:

• Solids: Definite shape and volume, particles tightly packed, fixed positions, vibrate in place.
• Liquids: Definite volume, but takes the shape of its container, particles close together but can move past each other.
• Gases: No definite shape or volume, particles are far apart, move freely and rapidly.

2. Particle Structures:

• Solids: Particles closely packed in regular arrangement, vibrate around fixed positions.
• Liquids: Particles are close but not fixed, they flow past one another.
• Gases: Particles are far apart, move randomly and quickly.

3. Changes of State:

• Melting: Solid to liquid (gain of energy).
• Boiling/Evaporating: Liquid to gas (gain of energy).
• Freezing: Liquid to solid (loss of energy).
• Condensing: Gas to liquid (loss of energy).

4. Effects of Temperature and Pressure on Gas Volume:

• Temperature: Increase in temperature increases gas volume (particles move faster, more space occupied).
• Pressure: Increase in pressure decreases gas volume (particles are pushed closer together).

5. Changes of State in Kinetic Particle Theory:

• Heating Curve: Energy input increases kinetic energy of particles, leading to changes in state.
• Cooling Curve: Energy loss decreases kinetic energy, causing changes in state.

6. Effects of Temperature and Pressure on Gas Volume:

• Temperature: Higher temperature increases kinetic energy, expanding gas volume.
• Pressure: Higher pressure compresses gas volume, reducing space between particles.

Diffusion

1. Description and Explanation:

• Diffusion is the process where particles move from an area of high concentration to an area of low concentration.
• Kinetic Particle Theory: According to this theory, particles are in constant motion due to their kinetic energy. In diffusion, particles move randomly, colliding with each other and spreading out to fill available space.
• Explanation: In a region of high concentration, particles collide frequently and spread outwards, while in a region of low concentration, particles move into the empty space, resulting in a net movement from high to low concentration until equilibrium is reached.

2. Effect of Relative Molecular Mass on Diffusion Rate:

• Relative Molecular Mass: Refers to the mass of a molecule compared to the mass of a carbon-12 atom, often denoted as "Mr."
• Impact on Diffusion: Lighter molecules diffuse faster than heavier ones because they have higher average speeds due to their lower mass.
• Explanation: Lighter molecules experience less resistance from other particles as they move through a medium, allowing them to move more quickly and cover greater distances in a given time compared to heavier molecules.

Happy Learning,

Team,

Smart Exam Resources

Detailed notes need to be purchased