Which of the following compounds is/are partially soluble or insoluble in NH4OH solution: (1) Fe(OH) — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Heating a chloride salt like NaCl with conc. H2SO4 and K2Cr2O7 produces orange-red chromyl chloride (CrO2Cl2) vapours (B). Step 2: Passing CrO2Cl2 vapours into NaOH solution forms a yellow solution of sodium chromate (Na2CrO4) (C). Step 3: Therefore, the yellow solution (C) is Na2CrO4, which corresponds to option (a).