Answer:
Explanation:The solubility of calcite and aragonite in carbonic acid has been determined over a CO2 concentration range from 10−4 to 10−3 molal and a temperature range from 10° to 70°C. The measurements were made in the absence of a gas phase in a newly developed conductometric solubility apparatus. The temperature derivative of solubility of calcite at constant CO2 concentration varies from −10−6 to −3 × 10−5 molal/°C, being a maximum for the highest CO2 concentration and temperature. The derivative of the solubility of calcite with respect to CO2 concentration at constant temperature has a value approximately 1 at very low CO2 concentrations and decreases as the CO2 concentration rises.
At low CO2 concentrations, the solubility of aragonite is the same as that of calcite within the experimental errors. At a CO2 concentration of 10−3 molal, aragonite is about 11 per cent more soluble than calcite.