Enthalpy of Reaction at lower temperatures [ENDORSED]

Boltzmann Equation for Entropy: $S = k_{B} \ln W$

Carlos Gonzales 1H
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Enthalpy of Reaction at lower temperatures

Could someone please explain a little more why enthalpy of reaction has a bigger role at lower T? Thanks.

Rachel Formaker 1E
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Re: Enthalpy of Reaction at lower temperatures

At lower temperatures, enthalpy of a reaction (ΔH or qP) has a bigger influence on the entropy of a reaction because of this equation:
$\Delta S = \frac{q}{T}$

When T is lower, ΔS is larger, meaning that q had a larger effect on entropy.

For example, if q=10 and T=1, ΔS =10, but if q=10 and T=10, then ΔS=1

So a lower temperature (T) means that the heat transferred (q) has a greater impact on entropy (ΔS).

Juanyi Tan 2K
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Joined: Fri Sep 29, 2017 7:05 am

Re: Enthalpy of Reaction at lower temperatures  [ENDORSED]

I find an explanation in the textbook to be helpful: just imagine how sneezing in a quiet environment will attract attention more than in a noisy environment. The energy transfer to a cool system where there is little thermal motion will result in a more noticeable change, leading to a greater entropy.

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