Volume change of ion pair formation: Rubidium nitrate and thallium(I) nitrate in water

Volume change for the formation of magnesium sulfate ion pairs at various temperatures

“…Eigen and Tamm43 have estimated the volume changes (±20%) for the individual steps as being °= 0, °= 14 and 18, and AVni°= 3_cm3/mol. Fisher45•46 has shown that these individual AV°'s yield a plot of RT log KA [where KA is calculated from eq 36] that is in excellent agreement with the experimental value (the slope gives 7.7 cm3/mol).…”

“…(3) By using the additivity principle <MM+, A") -(M+, X") + (N+, A-) -0v(N+, X"") 1 (13) Lee, 12 for example, estimated that of the free ions Mg2+ and S042~using the additivity principle <MMg2+, so42-) = (MMgcy + 0v(Na2SO4) ™ 2</>v(NaCl) (14) Equation 7 can be used to determine the fraction of• ions paired (1 -a) from <£v(obsd) provided ( +, A") and the volume change for formation of the ion pair can be estimated from solution theory. Millero has used an equation similar to eq 7 to estimate as in NaCl solutions8 and in seawater,® while Wirth and coworkers10'11 have used eq 7 to estimate the a's in R4NBr solutions10 and HS04~i n H2SO4 and NaHSCL solutions.11 Since one mbst estimate both for the ion pair and free ions to calculate (1 -a) or a, the results are not very reliable.…”

“…( the additivity estimates for the of the free ions Mg2+ and SO*2-[using eq 14 and 21] may be in error. By examining the observed </>v's of Na2S04 and K2S04 solution in terms of ion pairing, we have, respectively Na2S04) = 0v(2Na+, SO/-) + (1 -/ aS04-) (30) 0V(K2S04) -0V(2K+, S042-) + (1 -2) 0 ( 8 ) (31) where ai and a2 are, respectively, the fraction of free SO42-ions in Na2S04 and K2S04 solutions.…”

Apparent molar volumes and isentropic compressions of benzylalkylammonium ionic liquids in dimethylsulfoxide from 293.15 K to 328.15 K

“…On the other hand, the slope, S v shows that the ionion interactions. In generally, S v is positive, but it can be negative for some electrolytes; particularly for tetraalkylammonium salts [52][53][54], and also have been observed in this work, values of V m 1 , S v and B v for the ILs + DMSO systems were obtained at various temperatures by a linear regression analysis, and the results are listed in Table 4 along with their the standard deviations. It was found that the apparent molar volumes at infinite dilution, V m 1 for the ILs increase with the increase in the methyl group in the cation/ anion part of ILs at a particular temperature.…”

Standard partial molar volumes and viscosity B-coefficients of ionic liquids [Cnmim]Br (n=4, 6, 8) in alcohols at 298.15K

“…S v indicates the ion-ion interactions. In the concentration range studied, S v is generally positive but may be negative for some electrolytes, particularly for tetraalkylammonium salts [28][29][30]. B v describes deviation from Debye-Hückel limiting law (DHLL), which can be understood in terms of interactions among ion solvation shells.…”