A mixture of ferric alum, chrome alum and potash alum is dissolved in water and treated with an exce β Qualitative and Quantitative Analysis Chemistry Question
Question
A mixture of ferric alum, chrome alum and potash alum is dissolved in water and treated with an excess of NH3 solution and warmed with a mixture of NaOH and H2O2 and filtered. We will get:
π‘ 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 (BaSO4β), which is highly insoluble in gastric juices (Ksp ~ 1.1 x 10^-10) and safely excreted. This corresponds to option (b).