When a solid sample of Potassium Dichromate () is intensely heated with concentrated and a soluble m — d and f Block Elements Chemistry Question

💡 Solution & Explanation

This reaction outlines the classic Chromyl Chloride Test, used for the qualitative detection of chloride ions. When $K_2Cr_2O_7$ is heated with a chloride salt and concentrated sulfuric acid, it produces dense orange-red fumes of Chromyl Chloride ($CrO_2Cl_2$). The reaction is: $K_2Cr_2O_7 + 4NaCl + 6H_2SO_4 \rightarrow 2KHSO_4 + 4NaHSO_4 + 2CrO_2Cl_2 + 3H_2O$.