STPM Chemistry Form 6 Notes – Terminology and Concepts : Phases and Phase Change
November 6, 2009
Anybody having trouble remembering the difference between vaporisation, condensation, freezing, sublimation and the likes can look forward to this post/notes. It is not that students cannot understand the concepts, but usually student fail to recall the name of the phase change processes at crucial moments. And by crucial moments, I mean exams. Hence, Berry Berry Easy wants to impart another set of essential notes, this time on “Phases and Phase Change”
STPM Form 6 – Terminology and Concepts : Phases and Phase Change
Difference between the three phases:
|
Solid |
Liquid |
Gas |
|
Least kinetic energy (vibration and rotational forms and do not change their positions) |
More energetic than solid, yet not as energetic than gas (translation, vibrational and rotational forms) |
Most kinetic energy (translation, vibrational and rotation forms) |
Solid
Solid – a state having both a definite shape (fixed lattice structure) and a definite volume.
Unit cell – repeating structure subunits of a solid molecule (fixed lattice structure / crystal structure).
|
Solid |
|
| Simple cubic | One atom per repeating unit cell |
| Body-centred cubic | Two atoms per repeating unit cell |
| Face-centred cubic | Four atoms per repeating unit cell |
Liquid
Liquid – a state having a definite volume but no definite shape.
|
Liquid |
||||
|
Intermolecular forces |
Hydrogen bond | Polar interaction | Dipole moments | Van der Waals |
| Strongest | Strong yet weaker than hydrogen bond | Strong yet weaker than hydrogen bond and polar interaction | Weakest | |
Surface tension – the resistance of a liquid to an increase in its surface area.
Viscosity – the resistance of a liquid to flow / the resistance to flow by an object through the liquid.
Summary of phase change (berry berry important)
| Phase Change | Term |
| Liquid to gas | Vaporisation |
| Gas to liquid | Condensation |
| Solid to liquid | Melting |
| Liquid to solid | Freezing |
| Solid to gas | Sublimation |
| Gas to solid | Deposition |
Isothermal – conditions where the temperature of a system does not change.
Triple point – all three phases (solid, liquid and gas) can coexist simultaneously in the equilibrium
Critical point – highest temperature and pressure at which a liquid may be observed.
Supercritical fluid – Beyond critical point, it is impossible to distinguish between a gas and liquid.
Normal boiling point – temperature at which a material boils when the pressure is 1.00 atm.
Adapted from The Berkeley Review (2001) pg 65
Please also view the other berry related posts:
- STPM Chemistry Form 6 Notes – Terminology and Concepts: Liquid and Solid States (Part 5 – Final)
- STPM Chemistry Form 6 Notes – Terminology and Concepts: Liquid and Solid States (Part 2)
- STPM Chemistry Form 6 Notes – Terminology and Concepts: Liquid and Solid States (Part 3)
- STPM Chemistry Form 6 Notes- Terminology and Concepts : Gases and Gas Law
- STPM Chemistry Form 6 Notes – Terminology and Concepts: Liquid and Solid States (Part 1)
6 Responses to “STPM Chemistry Form 6 Notes – Terminology and Concepts : Phases and Phase Change”
thxn …
By janice ling on Nov 15, 2009
@ Janice – You’re very welcome. Feel free to request for resources also. I’ll try to queue it on my request list and process based on frequency of request. There’s nothing that makes me feel happier than helping out students.
By webmaster on Nov 15, 2009
plz post on tips and predictions for “STPM Physic 2009″
By JJ on Nov 16, 2009
@ JJ – Berry Berry Easy currently do not have the expertise to predict STPM Physics 2009. (We insist on publishing only high-quality tips for students rather than just copying them from the net. So we would rather not write anything than posting sub-standard articles) We intend to get outside collaboration with people who has the skills (urgently). Maybe you can register on our site, so that we can mail you when we have any tips on STPM Physics 2009.
By webmaster on Nov 16, 2009
hey i would like you to help me in my STPM esp chem n biolofy..im having a hard time in remembering and understanding the facts!! i need HELP before its too late =(
thanks alot
By Swan on Apr 12, 2010
@ Swan – Simple, just join Berry Berry Easy on facebook and under google friends connect. Also keep logging in Berry Berry Easy for more notes, tips and study techniques. If you want something more specific, you’ll have to write to us in more detail.
By BerryBerryTeacher on Apr 14, 2010