{"knowledge_schema": {"broad_category": "Chemistry \u2192 Coordination Chemistry \u2192 Complex Ion Equilibria", "refinement": "This problem involves calculating the concentration of free calcium ions in a solution containing a calcium-EDTA complex, using the stability constant of the complex.", "specific_scope": "The focus is on determining the concentration of calcium ions in a 0.02 M Ca-EDTA solution at a specific temperature and ideal conditions.", "goal": "Calculate the concentration of free calcium ions (Ca\u00b2\u207a) in the solution using the provided stability constant (KCa-EDTA)."}, "summary": "This problem is rooted in coordination chemistry, specifically in the area of complex ion equilibria. It requires calculating the concentration of free calcium ions in a solution containing a calcium-EDTA complex, given the stability constant of the complex. The goal is to find the concentration of Ca\u00b2\u207a ions in a 0.02 M Ca-EDTA solution at 25 \u00b0C, using the provided stability constant (KCa-EDTA = 5x10^10). This involves applying the relationship between the concentration of the complex and the free ions to derive the desired concentration."}