H2O (water) + CO2 (carbon dioxide) = H2 CO3 (carbonic acid)
H2 CO3 = H+ (hydrogen ion)+ H CO3- (bicarbonate ion)
Ca++ (calcium ion) + 2HCO3- = CaCO3 (calcite) + HCO3
Link to Periodic Table
Link to Fundamentals of Chemistry
H = 1
C = 12
O = 16
Ca = 40
Gram molecular weight of CO2 = 44 g
Gram molecular weight of Calcite = 100 g.
The ocean maintains a equilibrim concentration with respect to carbon dioxide in the atmosphere. When a molecule of calcite is precipitated from seawater, a molecule of carbon dioxide is ultimately removed from the atmosphere. Deposition of calcite as limestone beds serves as a storage reservoir (sink) for carbon within Earth's carbon cycle. How much (in weight percent) carbon is present in calcite? What weight percent of carbon is present in carbon dioxide?
The density of pure calcite (mass/unit volume) is 2.71 grams/cm3. However within limestone deposits, significant open volumes (unfilled spaces) are typically present, loweringthe overall density (bulk density) of the limestone beds. In this example, bulk density data acquired by deep sea drilling indicate (Link to bore data) an average bulk density of about 1.8 grams/cm3. What is this density value in kg/m3? How many kilograms carbon are present in a cubic meter of the limestone? Link to SI unit conversion.