Apparent molar isentropic compressions and expansions of solutionsElectronic supplementary information (ESI) is available: derivations of several key equations cited in the review. See http://www.rsc.org/suppdata/cs/a9/a908547e/

Abstract

Isentropic compressibilities of solutions κ_S are readily calculated using the Newton–Laplace equation together with measured speeds of sound and densities. The result is an apparent molar isentropic compression for a given solute-j, ϕ(K_Sj; def) and a limiting property, ϕ(K_Sj; def)^∞. This review examines the definition and calculation of ϕ(K_Sj; def) and ϕ(K_Sj; def)^∞, commenting on the related isentropic expansions, ϕ(E_Sj; def) and ϕ(E_Sj; def)^∞. We describe the thermodynamics which underpins the use of isentropic properties in the study of solute–solvent and solute–solute interactions.