Which of the following solid salt on heating with solid K2Cr2O7 and conc. H2SO4 orange red vapours a — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: This reaction is the classic chromyl chloride test used to detect the presence of chloride ions. Step 2: Heating a solid chloride salt (like NaCl) with solid potassium dichromate (K2Cr2O7) and concentrated sulfuric acid produces orange-red vapors of chromyl chloride (CrO2Cl2): 4NaCl + K2Cr2O7 + 6H2SO4 -> 2KHSO4 + 4NaHSO4 + 2CrO2Cl2 + 3H2O. Step 3: When these vapors are passed into a sodium hydroxide solution, they react to form yellow sodium chromate (Na2CrO4) solution. Bromides and iodides do not yield chromyl halides under these conditions. Thus, option (b) is the correct answer.