SPEED OF ULTRASOUND, DENSITY, AND ADIABATIC COMPRESSIBILITY FOR 3-METHYLPYRIDINE PLUS HEAVY-WATER IN THE TEMPERATURE-RANGE 293-313 K

The speed of ultrasound and density for 3-methylpyridine (1) + heavy w ater (2) were measured within the whole concentration range and at tem peratures from 293 to 313 K. Smoothing polynomials approximating the d ependencies of speed and density on temperature were determined. The s peeds of sound, densities, and adiabatic compressibilities (calculated using the Laplace formula) were plotted as functions of the mole frac tion x(1). The speed of sound and compressibility isotherms show singl e extrema and nearly common crossing points at low 3-methylpyridine co ncentrations, while the density decreases monotonically with increasin g x(1).