TY - JOUR
T1 - CO2 System Hydration and Dehydration Kinetics and the Equilibrium CO2/H2CO3 Ratio in Aqueous NaCl Solution
AU - Soli, Alan L.
AU - Byrne, Robert H.
PY - 2002/1/1
Y1 - 2002/1/1
N2 - Observations of pH on a millisecond time scale were used to obtain the CO 2 hydration rate, the H 2 CO 3 dehydration rate, the ionization constant of H 2 CO 3 , and the equilibrium ratio of CO 2 and H 2 CO 3 concentrations over a range of temperature (15–32.5 °C). In 0.65 molal NaCl, close to the ionic strength of seawater, the H 2 CO 3 dehydration rate constant ( k D ) is well represented by the equationlnkD(s−1)=30.15−(8018)T−1,">lnkD(s−1)=30.15−(8018)T−1, and the ionization constant, K a , for H 2 CO 3 followed the relationshiplogKa=−0.994−(610.5)T−1,">logKa=−0.994−(610.5)T−1, where T is the temperature (Kelvin scale). The equilibrium ratio ( K D ) of CO 2 and H 2 CO 3 concentrations at 25 °C was equal to 848. K D ranged from approximately 840 at 15 °C to 878 at 32.5 °C. Values of K D and k D were used to calculate the CO 2 hydration rate constant, k H . Over the temperature range of this work, k H was well represented by the equationlnkH(s−1)=22.66−(7799)T−1.">lnkH(s−1)=22.66−(7799)T−1.
AB - Observations of pH on a millisecond time scale were used to obtain the CO 2 hydration rate, the H 2 CO 3 dehydration rate, the ionization constant of H 2 CO 3 , and the equilibrium ratio of CO 2 and H 2 CO 3 concentrations over a range of temperature (15–32.5 °C). In 0.65 molal NaCl, close to the ionic strength of seawater, the H 2 CO 3 dehydration rate constant ( k D ) is well represented by the equationlnkD(s−1)=30.15−(8018)T−1,">lnkD(s−1)=30.15−(8018)T−1, and the ionization constant, K a , for H 2 CO 3 followed the relationshiplogKa=−0.994−(610.5)T−1,">logKa=−0.994−(610.5)T−1, where T is the temperature (Kelvin scale). The equilibrium ratio ( K D ) of CO 2 and H 2 CO 3 concentrations at 25 °C was equal to 848. K D ranged from approximately 840 at 15 °C to 878 at 32.5 °C. Values of K D and k D were used to calculate the CO 2 hydration rate constant, k H . Over the temperature range of this work, k H was well represented by the equationlnkH(s−1)=22.66−(7799)T−1.">lnkH(s−1)=22.66−(7799)T−1.
KW - Carbonic acid
KW - Hydration
KW - Dehydration
KW - Carbon dioxide system
KW - Kinetics
UR - https://digitalcommons.usf.edu/msc_facpub/1736
UR - https://doi.org/10.1016/S0304-4203(02)00010-5
U2 - 10.1016/S0304-4203(02)00010-5
DO - 10.1016/S0304-4203(02)00010-5
M3 - Article
VL - 78
JO - Marine Chemistry
JF - Marine Chemistry
ER -