Which of the following mixtures of ions in solution can be separated by using NH3 solution? — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Soluble barium salts like Ba(NO3)2 are highly toxic due to the physiological activity of free Ba2+ ions. Step 2: To prevent absorption in the digestive tract, the toxic Ba2+ ions must be precipitated as an extremely insoluble, non-toxic compound. Step 3: Adding sodium sulfate (Na2SO4) precipitates the barium as barium sulfate (BaSO4↓), which is highly insoluble in gastric juices (Ksp ~ 1.1 x 10^-10) and safely excreted. This corresponds to option (b).