Effect of temperature on carbonic acid acidity and the solubility of CaCO3.9Box 9-1 states that marine life with CaCO3 shells and skeletons will be threatened with extinction in cold polar waters before that will happen in warm tropical waters. The following equilibrium constants apply to seawater at 0° and 30°C, when concentrations are measured in moles per kilogram of seawater and pressure is in bars:
CO2(g) ‡Œ CO2(aq)

= 10 - 8.8324 mol kg -1 at 30°C

= 10 - 6,1391 mol-2 kg -2 at 30°C

= 10 - 6.3713 mol2kg -2 at 30°C
The first equilibrium constant is called KH for Henry's law (Problem 9-11). Units are given to remind you what units you must use.
(a) Combine the expressions for KH, Ka1, and Ka2 to find an expression for [CO23-] in terms of and [H+].
(b) From the result of (a), calculate [CO23-] (mol kg-1) at PCO2 = 800 μ bar and pH = 7.8 at temperatures of 0° (polar ocean) and 30°C (tropical ocean). These are conditions that could be reached around the year 2100 if we continue to release CO2 at the present rate.
(c) The concentration of Ca2+ in the ocean is 0.010 M. Predict whether aragonite and calcite will dissolve under the conditions in (b).

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CO(a)10-12073 mol kgbar at 0C 1.2075 mol kgar at 0°C 101 mol kg bar at 30 C Kj Pco, CO2 .6048 10 6.1004 mol kg-1 at O°C CO (aa)l CaCO,(s, aragonite)- Ca2+ + CO - 31 10-6-1113 mol kg 2 at 0 CaCO(s, calcite)Ca+ CO Kal Ca2CO 106 6.3652 mol kg 2 at 0°C