Speeds of sound and isothermal compressibility

of ternary liquid systems: Application of Flory's

statistical theory and hard sphere models

 

VIMLA VYAS

Thermo-acoustics Research Lab, Department of Chemistry, University

of Allahabad,  Allahabad 211 002, India

E-mail: vimlavyas@rediffmail.com

 

Abstract. Speeds of sound and densities of three ternary liquid

systems namely, toluene + $n$-heptane + $n$-hexane (I), cyclohexane + $n$-heptane

+ $n$-hexane (II) and $n$-hexane + $n$-heptane + $n$-decane (III) have been measured

as a function of the composition at 298.15 K at atmospheric pressure. The

experimental isothermal compressibility has been evaluated from measured

values of speeds of sound and density. The isothermal compressibility of

these mixtures has also been computed theoretically using different models

for hard sphere equations of state and Flory's statistical theory. Computed

values of isothermal compressibility have been compared with experimental

findings. A satisfactory agreement has been observed. The superiority of

Flory's statistical theory has been established quite reasonably over hard

sphere models.

 

Keywords. Flory's statistical theory; hard sphere models;

isothermal compressibility; ternary liquid systems.

 

PACS Nos 43.35.Bf; 61.20.Gy; 82.60.Lf