Apparent molar heat capacities and volumes of aqueous HClO4, HNO3, (CH3)4NOH and K2SO4 at 298.15 K

Apparent and partial molar heat capacities and volumes of aqueous HClO4 and HNO3 from 10 to 55 °C

“…Millero (10) cites standard state volumes from Zen (11) at 0, 10, and 25"C, of which the 10 and 25°C values are in good agreement with the present results. Smith-Magowan and Goldberg (12) of other results at room temperature, such as those by Singh et al (15) and Hovey et al (9) and the value based on a critical evaluation of data for perchloric acid and other perchlorate salts (7) that yielded C: = 25 k 1 J K-I mol-' for aqueous HC104. For these reasons, we believe that the present results are most reliable, and that the maximum uncertainty in the results occurs at 55°C and is approximately equal to k 10 J K-' mol-'.…”

“…Many of the room temperature standard state partial molar volumes and heat capacities for nitric and perchloric acids were discussed by Hovey et al (9) and the preferred values at 25°C are recommended over the present results. For temperatures above and below 25°C there are results from only a few studies that can be compared with the present work.…”

“…[9] to the B and C parameters obtained from fits to data for nitric acid was found to increase the overall standard deviation of the fits and thus was not used for refining the limiting standard state values.…”

“…Equation [7] was fitted to the experimental apparent molar properties listed in Table 1 at 10,40, and 55°C and at 25°C to the data from Hovey et al (9) to generate the values of YO,, By, and C y for nitric and perchloric acid that are listed in Table 3. It was found that the temperature dependence of the B y and Cy parameters for perchloric acid could be represented satisfactorily by equations of the form using only three of the four parameters without significant loss in the precision of the fits.…”

The thermodynamics of aqueous trivalent rare earth elements. Apparent molar heat capacities and volumes of Nd(ClO4)3(aq), Eu(ClO4)3(aq), Er(ClO4)3(aq), and Yb(ClO4)3(aq) from the temperatures 283 K to 328 K

“…In the series of papers (3,(22)(23)(24) describing their measurements on aqueous lanthanide salt solutions at T = 298.15 K, Spedding et al noted that the specific heat capacities of several sodium chloride solutions agreed with those reported by Randall and Rossini (25) to within 0.05 per cent. Randall and Rossini's values for the specific heat capacities and apparent molar heat capacities of NaCl(aq) in the range m = 0 to m = 1.0 mol·kg −1 are systematically lower than modern results (26) (27) on the basis of the usual convention {C°p ,2 (H + , aq) 0 0, V°2 (H + , aq) 0 0}, and these are listed in table 7. Our values for the conventional single-ion standard partial molar volumes V°2 at T = 298.2 K are in good agreement with those from the compilation by Shock and Helgeson.…”