(Photo Credit Coconino)
In GCE A-Levels, one of the topics that is always neglected by most Pre-U (JC) lecturers and tutors is Ideal Gas Law, or sometimes we call it Gaseous State.
It is a ‘small topic’ in terms of content, but it is ‘HUGE’ when it comes to student’s ability to handle the questions in Promo Exams and GCE A-Levels H2 Chemistry papers.
I realised that many JC1 and JC2 students are very afraid of this topic when it comes to their H2 Chemistry exams.
In Basic Chemistry syllabus such as GCE O-Level Chemistry (refer to SimpleChemConcepts.com for key chemistry concepts), we understand Gases are based on Kinetic Particle Theory, by assuming the following:
- There are no forces between the gas particles
- Particles are very far apart, and have alot of empty spaces
- Low densities and can be easily compressed
- Particles move in random motion and can move any direction
- Pressure of the gas is due to the particles hitting and bouncing off the walls of the container
- They have no shape
Now, the above is always true when it comes to Basic Chemistry, but for Advanced Level Chemistry such as A-Levels H2 Chemistry, we meed to understand more about concepts regarding Gases.
We need to realise that the above assumptions is hypothetical and gases are not always ideal – they are known as Real Gas.
The 4 basic assumptions of the Kinetic Theory as applied to Ideal Gas are:
- Gas particles (atoms or molecules) are of negligible size and volume
- Gas particles have negligible intermolecular forces of attraction
- Gas particles are in constant random motion
- Gas particles collide with each other which are elastic i.e. no loss in kinetic energy
The above is important as A-Levels H2 Chemistry students are required to be able to state the assumptions of the kinetic theory as applied to ideal gas.
Look out for the next post where i will share with you that most gases are Real Gas instead of Ideal Gas, and thus the limitations of ideality of gases.
Stay tuned for it!