IB Chemistry - Stoichiometry

IB Chemistry home > Syllabus 2025 > Stoichiometry > Gases

This section covers the behaviour of pure and mixtures of ideal gases. Chemical reactions involving gases are required.

Syllabus reference

Structure 1.5.1 - An ideal gas consists of moving particles with negligible volume and no intermolecular forces. All collisions between particles are considered elastic.

  • Recognize the key assumptions in the ideal gas model.


Tools and links

Structure 1.5.2 - Real gases deviate from the ideal gas model, particularly at low temperature and high pressure.

  • Explain the limitations of the ideal gas model.


  • No mathematical coverage is required.

Tools and links

  • Structure 2.2 - Under comparable conditions, why do some gases deviate more from ideal behaviour than others?

In Chapter 3.4