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New Member of Medicus / Chocolate Experiment

Lizzy Choi

Almaty International School




Hello, I am Lizzy Choi, a new member of Medicus representing Almaty International School in Kazakhstan.


Although I am currently a junior, I am very passionate about scientific studies (specifically Chemistry) and I hope to major in it in the future.


Discovering Medicus was very meaningful to me since the blog is initiated for students engaged in scientific studies worldwide to share their findings and interact with people who have common interests.

I hope to take away scientific knowledge and connections with others through Medicus!




The following is research on chemical structures based on a simple experiment conducted at Almaty International School, investigating the mechanism behind the structure of chocolate.


Chocolate is one of the few crystalline solids we consume. While crystalline solids are typically viewed as gemstones, they can be made of many materials.




Part 1.


Why does chocolate melt faster in our mouths than in our hands?


This question can be answered using a phase diagram.























Phase Diagram for water [adapted from [chemistryLearner.com]


The energy of particles is dependent on temperature and pressure. As the temperature increases, more heat energy is applied to the particles, which allows them to move freely with more kinetic energy, moving toward the gas phase. Pressure also has an effect: More external pressure causes the phase to move towards the solid phase due to the compression of particles.


As the water phase changes, chocolate also has its phases.































Polymorphs of chocolate and their melting points [from compoundchem.com]



The cocoa butter in chocolate undergoes phase changes as the temperature changes (consider it is at room pressure). The melting point of chocolate is around 36 degrees Celsius, which is very close to our internal body temperature of 37 degrees. Our hands, however, have a temperature around 27-32 degrees keeping chocolate solid.




Part 2.


Why does tempered chocolate solidify more easily?


It is due to the structural differences between the cocoa butter.


While the non-tempered chocolate has a unified form that makes it take longer to become the desired form, the tempered chocolate, on the other hand, has an added solid chocolate that works as a template for the rest.









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