METC Institute Blog

GAMSAT Key Concepts in Chemical Systems

Posted by Mat on Feb 1, 2019 10:59:24 AM

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In the previous blog-post and webinar, we discussed the key principles which underpin the
phenomena witnessed in the physical sciences. In this discussion we referred to the hierarchy of
sciences:

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The key implication of the hierarchy is that all sciences are premised on irreducible physical laws
(mathematics). Even the biological and physiological processes witnessed on a macroscopic level are at their core explainable by these physical laws. We do not explain such phenomenon using these laws however as the discourse related to these concepts is often on a more superficial plane.


Chemical science is more proximal to these physical laws than are the human sciences. It is therefore important to be able to explain chemical processes using physical laws. In a practical sense, this means asking ourselves why things occur the way they do. An added benefit of this method of thinking is that it often makes learning more efficient. For instance, consider the concept of electrostatics. By learning the principles that underlie electrostatics and atomic anatomy, much of the organic chemistry curriculum can be surmised without the need for rote learning. It follows therefore that an understanding of electrostatics is essential for the GAMSAT.

Fundamental to an understanding of chemical systems is comprehension of energy transfers during chemical reactions. Before considering energy transfer, principles students need to understand intuitively are that of the system (the chemical system itself), its surroundings (where the system is situated), and the universe (comprising both system and surroundings).

In the last webinar, energy was described as more-or-less a placeholder or method of accounting for the ability to do work. Along with the concept of work, heat and temperature were also described in their most elementary form. In this new context of chemical systems, temperature is more superficially described as a measure of the random motion of particles in a system (or the average kinetic energy). Heat is simply the transfer of energy due to establishing a temperature difference (this can also be though of as a gradient, or potential).

Those who are familiar with the above will collectively recognise the concepts as the basis of the
subject of chemical thermodynamics. Why is this subject important? Via its understanding, students can predict the way chemical reactions will propagate. Rather than rote memorising the negative and positive signs of Gibbs Free Energy, and the spontaneity of reactions, it is more important to understand why it is so.

In next week’s webinar, we will discuss how students can use these concepts to better understand problems they will face in Section III of GAMSAT.

Topics: gamsat, gamsatpreparation, gamsatscience