Apparent molal compressibilities of alcohols in aqueous solutions at different temperatures

Abstract

Apparent molal compressibilities (φ_k) of methyl, ethyl, <i>n</i>-propyl, isopropyl, <i>n</i>-butyl, isobutyl and <i>tert-</i>butylalcohols in aqueous solutions are reported at 2, 4, 6, 8 and 10°C<i>. </i> The variation of φ_k with concentration <i>(m) </i> has been interpreted in terms of effect of dissolved solute (alcohol) on water structure. The limiting apparent molal compressibilities (φ<img src='http://www.niscair.res.in/jinfo/equation49.gif' border=0>) of alcohols are also reported and interpreted in terms of hydrophobic interactions. In addition, parameter <i>P</i>_θ=(<img src='http://www.niscair.res.in/jinfo/derivative.gif' border=0>/<img src='http://www.niscair.res.in/jinfo/derivative.gif' border=0><i>P) </i> (<img src='/image/spc_char/delta.gif' border=0>θ_str), where <img src='/image/spc_char/delta.gif' border=0>θ_str is the structural contribution of shift in temperature of maximum density (Dθ), has been calculated as a function of concentration, It has been observed that <i>P</i>_θ can very well be used as a tool to express the relative structure strengthening ability of dissolved alcohols in water.