4 years ago

The stoichiometric dissociation constants of carbonic acid in seawater brines from 298 to 267 K

The stoichiometric dissociation constants of carbonic acid ( K 1 C and K 2 C ) were determined by measurement of all four measurable parameters of the carbonate system (total alkalinity, total dissolved inorganic carbon, pH on the total proton scale, and CO2 fugacity) in natural seawater and seawater-derived brines, with a major ion composition equivalent to that of Reference Seawater, to practical salinity (SP) 100 and from 25 °C to the freezing point of these solutions and −6 °C temperature minimum. These values, reported in the total proton scale, provide the first such determinations at below-zero temperatures and for SP > 50. The temperature (T, in Kelvin) and SP dependence of the current pK 1 C and pK 2 C (as negative common logarithms) within the salinity and temperature ranges of this study (33 ≤ SP ≤ 100, −6 °C ≤ t ≤ 25 °C) is described by the following best-fit equations: pK 1 C = −176.48 + 6.14528 S P 0.5 0.127714 SP + 7.396×10−5 S P 2 + (9914.37 − 622.886 S P 0.5 + 29.714 SP) T−1 + (26.05129 − 0.666812 S P 0.5 ) lnT (σ = 0.011, n = 62), and pK 2 C = −323.52692 + 27.557655 S P 0.5 + 0.154922 SP − 2.48396×10−4 S P 2 + (14763.2871014.819 S P 0.5 14.35223 SP) T−1 + (50.3858074.4630415 S P 0.5 ) lnT (σ = 0.020, n = 62). These functions are suitable for application to investigations of the carbonate system of internal sea ice brines with a conservative major ion composition relative to that of Reference Seawater and within the temperature and salinity ranges of this study.

Publisher URL: www.sciencedirect.com/science

DOI: S0016703717306269

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.