IB Chemistry HL 1.1.2 Kinetic Molecular Theory Question Bank
Practise IB Chemistry HL 1.1.2 with SL and HL questions on particle motion, state symbols and changes of state.
- Syllabus
- First assessment 2025
- Course
- Chemistry HL
- Level
- HL
Practise IB Chemistry HL 1.1.2 with SL and HL questions on particle motion, state symbols and changes of state.
Alkanes are commonly occurring organic compounds.
The first four straight chain alkanes are gases at room temperature.

Boiling points of straight chain alkanes
Explain why the volume occupied by a sample of propane increases sharply when the sample is heated up from 200 to 250 K at constant pressure.
boils/vaporizes
OR
molecules have sufficient energy to overcome intermolecular forces
gaseous molecules are further apart «than in liquid»
Marking guidance:
Accept gases have a «much»lower density than liquids for M2.
Do not award M2 unless a change of state is indicated.