D And F Block Elements

\(\mathrm{NaCl}\) reacts with conc. \(\mathrm{H}_2 \mathrm{SO}_4\) and \(\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7\) to give reddish fumes (B), which react with \(\mathrm{NaOH}\) to give yellow solution (C). (B) and (C) respectively are ;