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Beginners => PHREEQC Basics => Topic started by: peterwadeuk on July 10, 2017, 03:22:39 PM

Title: Coefficient A in Davies equation
Post by: peterwadeuk on July 10, 2017, 03:22:39 PM
Greetings good people,

I am attempting to calculate activity coefficients for aqueous reactions.

I understand that the Davies equation is the default equation for calculating the activity coefficients.

The Davies equation uses a coefficient "A" that I can't find in the database.

Is this a parameter that is embedded in the program or that is well-known?

All the best,
Peter
Title: Re: Coefficient A in Davies equation
Post by: dlparkhurst on July 10, 2017, 03:38:20 PM
It is relatively well known as a function of temperature. Its value is about 0.51 at 25C. You can print the value with the Basic function DH_A.
Title: Re: Coefficient A in Davies equation
Post by: peterwadeuk on July 11, 2017, 10:17:04 AM
Thank you David