Sodium in the above reaction is produced by

Analyze the question: The question asks which industrial process produces sodium metal. The "above reaction" isn't shown, but the question is about how sodium is manufactured, so we can answer from the concept.

Concept: Sodium is a very reactive metal (high in the reactivity series), so it cannot be extracted by chemical reduction with carbon. It is obtained by electrolysis of molten sodium chloride, in a cell called the Downs cell. Calcium chloride is added to lower the melting point of NaCl from about 801°C to about 600°C.

Step-by-step solution:

1. At the cathode (reduction): Na⁺ + e⁻ → Na (liquid sodium metal)
2. At the anode (oxidation): 2Cl⁻ → Cl₂ + 2e⁻ (chlorine gas)
3. Overall: 2NaCl(l) → 2Na(l) + Cl₂(g)

Checking the options:

• A. Browning process: not a recognised industrial process for sodium.
• B. Chlor process: not the name of the sodium process. The related industry is the chlor-alkali process, which electrolyses brine (aqueous NaCl) to give NaOH, Cl₂ and H₂, not sodium metal.
• C. Downs process: electrolysis of molten NaCl, which gives sodium. ✔
• D. Bosch process: this relates to hydrogen production (and is sometimes linked to the reduction of CO₂ with H₂), not sodium.

Answer: C. Downs process

Tip: Remember "Downs = Dry (molten) NaCl → Na". If the NaCl is in water (brine), you get NaOH, not sodium metal, because water is reduced instead of Na⁺. Also, Haber = ammonia, Contact = sulphuric acid, Ostwald = nitric acid, Downs = sodium.