Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The densities, rho, ultrasonic speeds, u and viscosities, eta of the drug isoniazid in water and in aqueous-d-glucose/d-sucrose (5 wt% and 10 wt% glucose/sucrose in water) solvents were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and at atmospheric pressure. The rho, u and eta data have been used to calculate apparent molar volumes, Vphi, limiting apparent molar volumes, Vphi*, apparent molar compressibilities, Ks,phi, limiting apparent molar compressibilities, Ks,phi*, transfer volumes, Vphi,tr* and transfer compressibilities, Ks,phi,tr*. The viscosity data have been used to determine Falkenhagen Coefficients, A and Jones-Dole coefficients, B. The calculated parameters have been discussed in terms of various solute-solute and solute-solvent interactions prevailing in these solutions. The structure making/breaking ability of isoniazid in these solutions has been examined by using the sign of dB/dT. Furthermore, the Gibbs energies of activation of viscous flow per mole of solvent, deltamu1* and per mole of solute, deltamu2*, enthalpies, deltaH* and entropies, deltaSo of activation of viscous flow, were also calculated and discussed in terms of transition state theory.