(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!
Could you please list the limitations of the ideal gases also