which of the following is present in highest concentration in soft water?
Calcium carbonate is relatively insoluble in water, but. dissolves more readily in water containing significant. levels of dissolved carbon dioxide.1. The concentration of calcium ions (Ca2+) in freshwater is found in a range of 0 to 100 mg/L, and. usually has the highest concentration of any freshwater cation. A level of 50 mg/L is. recommended as the upper limit for drinking water.