Activity coefficient Henrian

It can be immediately seen that for components exhibiting Raoultian behaviour, the activity coefficient is equal to unity. The Henry s law constant k is nothing but the activity coefficient Yj. Noting that Henrian behaviour is exhibited when the component i is present in very low concentrations, the constant is also expressed in this case as y and is known as the activity coefficient at infinite dilution. Henry s law may now be stated as... 

Find Henrian activity coefficient, Yq of liquid Fe-C solutions at 1,600°C. 

It is obvious from the equation that the activity coefficient of A at infinite dilution of A, i.e., the Henrian activity coefficient, yA° is given by... 

The activity of silicon in a binary Fe-Si liquid alloy containing Nsl = 0.02 is 0.000022 at 1,600°C relative to the Raoultian standard state. The Henrian activity coefficient y% is experimentally determined to be 0.0011. 

Fugacity, also see below f = Henrian activity coefficient F = Free Energy, Gibbs Free Energy F = Farady Constant g = Gas... 

Assuming that the solution obeys Henry s law up to 1 wt % of A, then h is unity at this concentration, and thus the standard state is the 1 wt% solution. Deviations from this equality of activity and weight percent are measured in terms of Henrian activity coefficient relative to the infinitely dilute, weight percent standard state, i.e. 

Though in both the equations (6.27) and (6.30) h and f have been used for denoting the Henrian activity and activity coefficient of A respectively, in Eq.(6.27) they signify relative to the infinitely dilute, atom fraction standard state, while in Eq.(6.30) they are relative to the infinitely dilute, weight percent standard state. 

In these expressions Y and v refer to the solute species and X and x to the solvent Nx and Yy are the mole fractions. With ntot as the total number of moles and y the number of moles Y, b an interaction parameter of the system, y the activity coefficient, and a Henrian activity coefficent, the equation for the partial molar heat of mixing is derived as... 

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