The solubility of calcium carbonate CaCO3 in water at 25C is quite low, approximately 15 mg/L or 0.015 g/L. This means that only 15 milligrams of calcium carbonate can dissolve in 1 liter of water at this temperature.Several factors determine the solubility of calcium carbonate in water:1. Temperature: The solubility of most salts, including calcium carbonate, typically increases with temperature. However, the effect of temperature on the solubility of CaCO3 is relatively small.2. Pressure: The solubility of calcium carbonate is slightly affected by pressure. An increase in pressure can cause more calcium carbonate to dissolve in water, but the effect is not significant.3. pH: The solubility of calcium carbonate is highly dependent on the pH of the solution. In acidic conditions low pH , calcium carbonate dissolves more readily, forming calcium ions Ca2+ and carbonate ions CO3 2- . In alkaline conditions high pH , calcium carbonate is less soluble and tends to precipitate out of the solution.4. Presence of other ions: The solubility of calcium carbonate can be affected by the presence of other ions in the solution. For example, the presence of magnesium ions Mg2+ can increase the solubility of calcium carbonate by forming more soluble magnesium carbonate MgCO3 .5. Complexation: The presence of complexing agents, such as certain organic compounds, can increase the solubility of calcium carbonate by forming soluble complexes with calcium ions.In summary, the solubility of calcium carbonate in water at 25C is approximately 15 mg/L, and it is influenced by factors such as temperature, pressure, pH, presence of other ions, and complexation.