# Wilke-Chang equation

Calculates the tracer diffusion coefficients of a given solute in a solvent using the Wilke-Chang equation.

K
cP
cm3 mol-1
g mol-1
cm2 s-1

#### Notes

This calculator uses the Wilke-Chang equation to calculate the diffusion coefficients of a solute in a solvent.

$D_\mathrm{12} = 7.4 \times 10^{-8} \frac{(\phi M_1)^{0.5} T}{\mu_1 (V_\mathrm{Tc,bp,2})^{0.6}}$

$V_\mathrm{Tc,bp,2} = 0.285 \times V_\mathrm{c,2}^{1.048}$

where $$D_\mathrm{12}$$ is the binary diffusion coefficient in cm2/s, $$\phi$$ is the association factor of the solvent (nondimensional), $$T$$ is the temperature in K, $$M_\mathrm{1}$$ is the molecular weight of the solvent in g/mol, $$\mu_1$$ is the solvent viscosity in cP, $$V_\mathrm{Tc,bp,2}$$ is the solute molar volume at normal boiling temperature in cm3/mol, and $$V_\mathrm{c,2}$$ is the solute critical volume in cm3/mol.

#### References

C.R. Wilke, P. Chang, Correlation of diffusion coefficients in dilute solutions, AICHE J., 1955, 1(2) 264-270.