Specific Heat: Degree of Freedom & Energy Storage

[hwall95]

Homework Statement

Okay I have to write an EEI (Extended Experimental Investigation) for physics in relation to which radiator coolant is best from a thermodynamics point of view, thus the specific heat of the coolant is the main focus. But to incorporate more depth into the report, I was going to try and explain why water and ammonia have high specific heats, while etheylene glycol does not. But before I can explain either I am trying to understand both degrees of freedom and Equipartition of Energy theory.

Homework Equations

So basically there's not equations, but there question is, if I am on the right track of understanding it. I find it a bit complex to teach myself it off wikepedia anyways.

The Attempt at a Solution

Okay so far my understand is that different polyatomic molecules have different amount of degrees of freedom in which they can move (is there more then four for non-quantum applications as in one type of movement). Then depending on the polyatomic molecule (since all my data which I found was using polyatomic substances) number of ways it can store kinetic energy such as rotational kinetic energy, translational kinetic energy, vibrational kinetic energy, oscillating kinetic energy, the higher its specific heat as it needs to fill one layer at the time. So am I on the right track or have I confused myself somewhere? hahahah

So if anyone has anytime to spare, to share any wisdom, it would be much appreciated.

Links Used:
http://www.tutorvista.com/content/physics/physics-iii/heat-and-thermodynamics/molar-specific-heats.php
http://en.wikipedia.org/wiki/Equipartition_theorem
http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/eqpar.html
http://en.wikipedia.org/wiki/Degrees_of_freedom_(physics_and_chemistry)
http://en.wikipedia.org/wiki/Specific_heat#Theory_of_heat_capacity
http://en.wikipedia.org/wiki/Statistical_mechanics

 

[mark726]

Hello, thank you for sharing your ideas and progress on your EEI project. It seems like you have a good understanding of the concepts of degrees of freedom and the equipartition of energy theory. However, it may be helpful to clarify a few points.

Firstly, in terms of degrees of freedom, it is important to note that for non-quantum applications, there are typically 3 translational degrees of freedom (movement in x, y, and z directions) and 2 rotational degrees of freedom (rotation around two axes). These are the most relevant degrees of freedom for discussing specific heat, as they contribute to the kinetic energy of the molecules.

Secondly, while it is true that the more degrees of freedom a molecule has, the higher its specific heat will be, it is not necessarily accurate to say that it needs to "fill one layer at a time." Specific heat is a measure of how much energy is required to raise the temperature of a substance, and it is influenced by the average energy per degree of freedom of the molecules in the substance. So, molecules with more degrees of freedom will require more energy to raise their temperature, and therefore have a higher specific heat.

Lastly, it may be helpful to also consider the intermolecular forces at play in different coolants. For example, water has strong hydrogen bonding which contributes to its high specific heat, while ethylene glycol has weaker intermolecular forces and therefore a lower specific heat.

I hope this helps and I wish you luck with your project!