(A) Sodium carbonate is manufactured by Solvay process ⇒ (iv) of List-ll. Solvay process's reactions are as follows In Solvay's process, first ammonia (NH3​) reacts with CO2​ and H2​O to give ammonium bicarbonate (NH4​HCO3​). This bicarbonate react with NaCl to give sodium bicarbonate (NaHCO3​) along with ammonium chloride (NH4​Cl). At last, NaHCO3​ is heated to form sodium carbonate as major product. NH3​+CO2​+H2​O→NH4​HCO3​NH4​HCO3​+(Brine)NaCl​⟶NaHCO3​↓+NH4​Cl2NaHCO3​→Δ2​→SodiumcarbonateNa2​CO3​​+CO2​+H2​O (B) Titanium is purified by van-Arkel method ⇒ (iii) of List-II van-Arkel method Crude titanium 780KI2​​ Til 4​(g)1800K​(Pure)Ti​+2I2​ (C) Chlorine is manufactured by Deacon process ⇒ (i) of List-II. Deacon process 4HCl(g)+[Air]O2​(g)​CuCl2​ (catalyst) 723K​Chlorinegas2Cl2​​+2H2​O(g) (D) Sodium hydroxide is manufactured by Castner-Kellner cell ⇒ (ii) of List-II. Castner-Kellner cell reaction Electrolyte used is brine, saturated NaCl solution. Cathode (Hg) : Na++e−⟶NaHg​Na/Hg Anode (carbon) : Cl−+e−⟶21​Cl2​↑2Na/Hg+2H2​O⟶Sodiumhydroxide2NaOH​+2Hg+H2​↑