Which of the following pair of cations can be separated by excess NaOH solution ? — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Examine the reactants: calcium chloride (CaCl2) and sodium sulfate (Na2SO4) are highly soluble salts. Step 2: Under highly dilute or specific non-precipitating conditions, they may coexist without precipitation of calcium sulfate (which is moderately soluble). The textbook specifies this process as 'No reaction'. Step 3: Since there is no observable reaction or solid phase transformation under these conditions, this is classified as no reaction (type D), matching option (d).