c
Solid potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride gives orange red vapours of a volatile oily liquid \(Cr{O_2}C{l_2}\) \(K_2Cr_2O_7 + 4NaCl + 6H_2SO_4\) \(\longrightarrow\)  \(\begin{array}{l} 2KHS{O_4} + 4NaHS{O_4} + 2Cr{O_2}C{l_2}\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\rm{chromyl \,chloride}} \end{array}\)