Journal article
Ion hydration and association in aqueous potassium phosphate solutions
The Journal of Physical Chemistry B, Vol.119(16), pp.5270-5281
2015
Abstract
Ionic hydration and ion association in aqueous solutions of KH2PO4, K2HPO4, and K3PO4 at 25 °C up to high concentrations have been investigated using dielectric relaxation spectroscopy (DRS). The three phosphate anions were found to be extensively hydrated, with total hydration numbers at infinite dilution of ∼11 (for H2PO4-), ∼20 (HPO42-), and ∼39 (PO43-). These values are indicative of the existence of a second hydration shell around HPO42- and especially PO43-. Two types of hydrating water molecules could be quantified: irrotationally bound (ib, H2O molecules essentially "frozen" on the DRS time scale) and "slow" (loosely bound water molecules with identifiably slower dynamics than bulk water). For H2PO4- over the entire concentration range and for HPO42- and PO43- at concentrations c ≲ 1 mol L-1, only "slow" H2O was detected; however, at higher concentrations of the latter two anions, an increasing fraction of ib water appears, making up ∼50% of the total hydration number close to the saturation limit of K2HPO4. Contrary to common belief, all three salts showed significant ion pair formation, with standard association constants of the 1:1 species increasing in the order: KH2PO40(aq) < KHPO4-(aq) < KPO42-(aq). The main type of ion pair in solution shifted from solvent-shared ion pairs (SIPs) to double-solvent-separated ion pairs (2SIPs) in the same sequence.
Details
- Title
- Ion hydration and association in aqueous potassium phosphate solutions
- Authors/Creators
- A. Eiberweiser (Author/Creator)A. Nazet (Author/Creator)G. Hefter (Author/Creator)R. Buchner (Author/Creator)
- Publication Details
- The Journal of Physical Chemistry B, Vol.119(16), pp.5270-5281
- Publisher
- American Chemical Society
- Identifiers
- 991005540576707891
- Copyright
- © 2015 American Chemical Society
- Murdoch Affiliation
- School of Engineering and Information Technology
- Language
- English
- Resource Type
- Journal article
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Metrics
147 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- International collaboration
- Citation topics
- 2 Chemistry
- 2.89 Ionic, Molecular & Complex Liquids
- 2.89.677 Liquid Water
- Web Of Science research areas
- Chemistry, Physical
- ESI research areas
- Chemistry