Solubilities of pyruvic acid and the lower (C1-C6) carboxylic acids. Experimental determination of equilibrium vapour pressures above pure aqueous and salt solutions

Gas/Aerosol Distribution of Formic and Acetic Acids

“…In any of the three cases formate and acetate are predicted to be only minor constituents of the particles. This is consistent with the findings of Khan et al (1995). It is also found that the influence of formic and acetic acids on aerosol chemistry is small.…”

“…Such approximations have b e e n used by Clegg a n d Brimblecombe (1988) activity coefficients of the aqueous molecules in a concentrated solution are generally larger than 1.0 as a result of the salting effect that tends to reduce the gas solubilities in the solution (e.g., Khan et al 1995). However, it should be noted that an increase of gas solubilities in the presence of salts has also been observed (Ohe 1991).…”

Tropospheric sources and sinks of gas-phase acids in the Colorado Front Range

“…3). While both HNO 3 and pyruvic acid readily partition into the aqueous-phase (H = 2.1×10 5 and 3.1×10 5 mol L −1 atm −1 for HNO 3 and pyruvic acid, respectively) (Khan et al, 1995;Schwartz and White, 1981), we estimate that aqueous-phase partitioning is a negligible sink for both compounds. Photochemistry is not a major sink of HNO 3 , but pyruvic acid readily undergoes photolysis -corresponding to a typical atmospheric lifetime of a few hours (Grosjean, 1983).…”

“…The high Henry's law constants (H ) of these acids suggest that aqueous-phase partitioning (aqueous aerosols, fog and cloud droplets, etc.) would be favorable (H = 5.5 × 10 3 , 5.7 × 10 3 , 4.7 × 10 3 , and 2.2 × 10 3 mol L −1 atm −1 for formic, propionic, butyric, and valeric acids, respectively, at T = 298 K) (Khan et al, 1995). However, this was likely not a significant sink given the arid climate of the Front Range.…”

Observational Insights into Aerosol Formation from Isoprene

“…28 The Henry's law constant for MAE has not been measured so we estimate it here using EPA's HENRYWIN program. 64 The estimate can be refined by comparison with analogous compounds whose k H cp values have been measured, e.g., 2-methyl propanoic acid (8.9 × 10 7 M atm −1 ) 69 giving an estimate of 7.5 × 10 6 M atm −1 , a factor of 20 lower than IEPOX.…”