Solute-solvent interactions in water-tert-butyl alcohol mixtures. III. ?G ?, ?H ?, and ?S ? for dissociation of aliphatic carboxylic acids in water-rich media

Acid–Base Property of N-Methylimidazolium-Based Protic Ionic Liquids Depending on Anion

“…Δ H app,0 ° for CH 3 COOH was 26 kJ/mol less negative than Δ H app,0 ° for HCOOH. This gap in Δ H app,0 ° is greater than that in their dissociation enthalpies in water; small and similar values of ±1 kJ/mol have been reported for both CH 3 COOH and HCOOH . We can consider that the addition of a small amount of Mim into neat HA involves the following processes: (1) isolation of monomeric HA and Mim as possible reactants into the gas phase, (2) proton transfer reaction from HA to Mim in the gas phase, and (3) solvation of the possible products of A – and HMim + by neat HA.…”

Calorimetric investigation of hydrolyzed copolymers of maleic anhydride with butyl and lower alkyl vinyl ethers

“…The depression of deprotonation enthalpy and entropy by alkyl substitution has been observed in simple aliphatic acids, such as the formic, acetic, and propionic acid series. 24,25 Even though this effect has been recognized for decades, its mechanism is still uncertain. One recent treatment attributes the changes to the alteration of the hydration layer around the acid molecule with alkyl substitution.26 Between a = 0.8 and a = 1.2 the enthalpy and entropy curves of the ethyl copolymer show drops similar to those of the methyl copolymer.…”

Enthalpies and Entropies of Transfer of Electrolytes and Ions from Water to Mixed Aqueous Organic Solvents

“…Potentiometric measurements reported by Dash and Samanta 179 for a number of silver salts at low cosolvent concentrations contained too little useful information to justify their inclusion. Data have also been reported for the enthalpies of dissociation of water 180 and various carboxylic acids 18 Δ t H °(MX, w → w + t -BuOH)/kJ mol -1 , 298.15 K, as a Function of 100 x t -BuOH MXΔ sln H °24681012142030507090100ref HCl [2.5] [4.4] [5.6] [6.0] [5.4] [3.7] [0.9] [−0.2] [−2.3] 146 HCl 2.3 3.3 3.1 2.0 0.3 −1.2 −1.9 160 HCl [6.0] [7.9] [7.1] [5.0] [2.9] [2.2] [4.3] 114, 161 HCl {2.3} {3.3} {3.1} {2.0} {0.3} { − 1.2} { − 1.9} HBr 2.5 3.1 2.2 0.4 −1.6 −3.3 −4.2 160 HBr (2.9) (4.3) (4.4) (3.9) (2.5) (0.7) (−1.4) −7.6 −34.7 −75.8 −41.9 116 HBr [6.3] [7.6] [5.7] [1.7] [−3.3] [−8.4] [−12.4] [−8.6] 161, 114 HBr 2.7 3.7 {3.3} {2.2} { − 0.6} { − 1.3} { − 2.8} <...…”