Henry's law coefficients of formic and acetic acids

✍ Scribed by Bryan J. Johnson; Eric A. Betterton; David Craig

• Publisher: Springer Netherlands
• Year: 1996
• Tongue: English
• Weight: 379 KB
• Volume: 24
• Category: Article
• ISSN: 0167-7764
• DOI: 10.1007/bf00162406

✦ Synopsis

The Henry's law constants, KH, of dilute aqueous formic and acetic acids were determined experimentally as a function of concentration and temperature using a new counterflow packedcolumn technique. KH was found to be (8.9 + 1.3) x 103 and ( 4.1 :t: 0.4) x 103 M atm-1 at 25 ° C for HCOOH and CH3COOH, respectively. The reaction enthalpies, AH, were found to be -51 4-2 kJ tool-~ and -52 4-1 kJ tool-l for formic and acetic acid, respectively, These are in good agreement with calculated thermochemical values.

Whereas the Kt/ values are in reasonably good agreement with certain other experimentally determined values, Kn (HCOOH) is two to three times higher than calculated thermochemical values while KH (CH3COOH) is lower than the two calculated values.

The 'best' experimental values appear to be (11 + 2) x 103 Matm-1 and (7 ~ 3) x 103 M atm-T for HCOOH and CH3COOH, respectively.