TY - JOUR
T1 - Ionic dissociation of aqueous hydrobromic acid. Part 2. - Estimate from proton magnetic resonance data at 6-60°C
AU - Soffer, Neomy
AU - Marcus, Yizhak
AU - Shamir, Jacob
PY - 1980
Y1 - 1980
N2 - Proton nuclear magnetic resonance measurements have been made on aqueous hydrobromic acid solutions at 6-60°C and over a concentration range ≈ 1-20 mol kg-1. The data have been interpreted according to the Gutowsky and Saika method, considering several options for the limiting slopes at low and high concentrations. The chemical shift of hydronium ions relative to water, SH3O+, can be obtained from extrapolation of data to zero concentration [option (a)], or from a correlation of data on other acids with the anion volume [option (b)]. The chemical shift of the undissociated acid, sHBr, can be equated with that of liquid hydrogen bromide [option (c)], or can be obtained from the data at the highest aqueous acid concentrations [option (d)]. The combination of options (a) and (d) is preferable to the other combinations of options. The data yield a mean degree of association over the temperature range studied of 2% at 4 mol kg-1, of 6% at 8 mol kg-1, of 11% at 12 mol kg-1, of 20% at 16 mol kg-1 and of 34% at 20 mol kg-1 (with a relative uncertainty of ±25%).
AB - Proton nuclear magnetic resonance measurements have been made on aqueous hydrobromic acid solutions at 6-60°C and over a concentration range ≈ 1-20 mol kg-1. The data have been interpreted according to the Gutowsky and Saika method, considering several options for the limiting slopes at low and high concentrations. The chemical shift of hydronium ions relative to water, SH3O+, can be obtained from extrapolation of data to zero concentration [option (a)], or from a correlation of data on other acids with the anion volume [option (b)]. The chemical shift of the undissociated acid, sHBr, can be equated with that of liquid hydrogen bromide [option (c)], or can be obtained from the data at the highest aqueous acid concentrations [option (d)]. The combination of options (a) and (d) is preferable to the other combinations of options. The data yield a mean degree of association over the temperature range studied of 2% at 4 mol kg-1, of 6% at 8 mol kg-1, of 11% at 12 mol kg-1, of 20% at 16 mol kg-1 and of 34% at 20 mol kg-1 (with a relative uncertainty of ±25%).
UR - http://www.scopus.com/inward/record.url?scp=0344099257&partnerID=8YFLogxK
U2 - 10.1039/F19807602347
DO - 10.1039/F19807602347
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AN - SCOPUS:0344099257
SN - 0300-9599
VL - 76
SP - 2347
EP - 2361
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
ER -