Kinetic Molecular Theory & Phase Changes — Drills · Grade 11 Science
Chapter: States of Matter & GasesWhat these drills covers
By the end of Kinetic Molecular Theory & Phase Changes you should be able to:
- I can state the assumptions of the kinetic molecular theory and use them to explain how gases behave.
- I can describe the particle arrangement in solids, liquids, and gases, and interpret heating curves and phase diagrams for all six phase changes.
6 questions, multiple choice, numeric and written answer, each with a worked explanation.
Vocabulary used: kinetic molecular theory (KMT), kinetic energy, phase change, heating curve, heat of fusion, heat of vaporization, phase diagram, sublimation.
Problem 1
- Collisions between particles are perfectly elastic
- Gas particles attract each other strongly
- Gas particles are in constant, random motion
- The volume of the particles themselves is negligible
Answer and explanation
Gas particles attract each other strongly
An ideal gas is assumed to have NO attractions between particles; the other three statements are genuine KMT assumptions.
Problem 2
- plasma
- solid
- liquid
- gas
Answer and explanation
liquid
In a liquid, particles stay close but are free to move past each other, so it flows while keeping a fixed volume.
Problem 3
Answer and explanation
373 K
K = °C + 273 = 100 + 273 = 373 K.
Problem 4
- deposition
- condensation
- freezing
- sublimation
Answer and explanation
sublimation
Sublimation (solid to gas) absorbs energy; condensation, freezing, and deposition all release it.
Problem 5
Answer and explanation
A phase change is occurring. The added energy is being used to break the attractions holding the particles together (raising their potential energy) rather than speeding the particles up, so the temperature — which measures average kinetic energy — stays constant until the change is complete.
Problem 6
Answer and explanation
-273 °C
°C = K − 273 = 0 − 273 = −273°C (more precisely −273.15°C).