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I was thinking about temperature, and had a thought. Temperature is proportional to the average temperature per particle. If you split a particle, you have twice as many particles but only the same amount of energy. So, each half would only have (on average) half of the original energy.

The first example I though of would be salt dissolving in water, which I looked up and it is slightly endothermic. Unfortunately there are a lot of factors at play that both increase and decrease the energy during that reaction so it isn't exactly conclusive. Plus, if this were correct you would have half of the temperature in kelvin, which is an enormous temperature drop which you definitely do not see in dissolving salt.

Did I make a mistake or does a particle splitting actually decrease the temperature? If so, why does salt dissolving not cause a massive temperature drop?

rtpax
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Yes, if particles are splitted in half, temperature will decrease to a half. But when you dissolve salt in water, each sodium and chlorine molecule will by surrounded by water molecules. https://en.wikipedia.org/wiki/Solvation_shell It will increase the average energy of a particle thus increasing the temperature. In the case of sodium chloride the main effect will be the first.

Sartem Cacartem
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  • I see, so the water around the ion strongly enough to essentially act like a single large particle. That makes a lot of sense, thanks for the andwer – rtpax Oct 04 '19 at 00:06