Activity and Concentration

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Diane Kang 2F
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Joined: Thu Sep 27, 2018 11:18 pm

Activity and Concentration

Postby Diane Kang 2F » Mon Jan 07, 2019 4:13 pm

During class, Dr. Lavelle mentioned the relationship between activity and concentration, introducing the relationship a = γ (concentration).

What exactly is activity? And how does activity relate to why we omit units for molar concentration when calculating equilibrium constants?

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Re: Activity and Concentration

Postby Chem_Mod » Mon Jan 07, 2019 4:22 pm

We do not go into detail on chemical activity, but it is a unitless quantity that we have replaced (by approximation) with concentration. This means for equilibrium constants, do not use units.

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Re: Activity and Concentration

Postby Chem_Mod » Mon Jan 07, 2019 4:24 pm

Activity is essentially how a certain concentration of a solution is acting relative to its actual concentration. It comes from the fact that very concentrated solutions will either express a property more highly or less highly due to non-ideal interactions. It is a little bit more conceptual than you need to know for the course, just know that it is a concept that is used to describe non-ideal solutions and how the components within behave.


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