ISSN:
1572-8927
Keywords:
Microcalorimetry
;
alcohols
;
aqueous solution
;
partial volume
;
partial heat capacity
;
hydration
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Using a precise technique of scanning microcalorimetry the heat capacity differences between water and dilute aqueous solutions of ethanol, n-propanol, n-butanol and n-pentanol were measured from 5 to 125°C and the partial molar heat capacities of these substances in water were determined. It was found that the heat capacity increment for alcohol disolved in water is proportional to the number of the-CH 2 − groups and decrease with a temperature increase. The heat capacity increment of hydration of non-polar groups is shown to be positive and large at room temperature and decreases in magnitude as the temperature increases. In contrast, the heat capacity increment of hydration of polar groups is negative at room tempreature and increases as the temperature increases. From the temperature dependence of the heat capacity increment one can assume that the water molecules solvated by the non-polar groups of the alcohols behave in a non-cooperative manner.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00647893
Permalink
