Which of the following pairs of chlorides will NOT yield red vapors of chromyl chloride when heated — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

The chromyl chloride test relies on the generation of $Cl^-$ ions which react with chromic acid. Heavy metal chlorides such as $HgCl_2, AgCl, PbCl_2$, and $SnCl_2$ possess significant covalent character. Consequently, they do not ionize sufficiently to provide the necessary $Cl^-$ concentration, failing to produce the characteristic red vapors of $CrO_2Cl_2$.