JEE Main · 2021 · 26 Feb 2021 · Shift 2 · s-Block Elements

Sodium carbonate is manufactured by the Solvay process, in which ammonia and carbon dioxide are passed through brine to precipitate $\mathrm{NaHC}{\mathrm{O}}_3$, which is then calcined. Titanium is refined by the van Arkel method, where the crude metal is converted to volatile $\mathrm{Ti}{\mathrm{I}}_4$ and the iodide is decomposed on a hot tungsten filament. Chlorine is made in the Deacon process by air oxidation of $\mathrm{HCl}$ over a copper chloride catalyst. Sodium hydroxide is made by the Castner-Kellner process, the electrolysis of brine in a cell with a mercury cathode. So sodium carbonate goes with Solvay, titanium with van Arkel, chlorine with Deacon and sodium hydroxide with Castner-Kellner.