Match List-I with List-II

List-I	List-II
a. Sodium Carbonate	i. Deacon
b. Titanium	ii. Caster-Kellner
c. Chlorine	iii. Van-Arkel
d. Sodium hydroxide	iv. Solvay

1. Solvay process: The main industrial procedure for producing sodium carbonate(${\mathrm{Na}}_2{\mathrm{CO}}_3$) is known as the Solvay process or ammonia-soda process.
2. Van-Arkel: The van Arkel-de Boer process, also known as the iodide process or crystal-bar technique, was the first industrial method used to produce zirconium, titanium, and other metals in their purest forms for commercial use.
3. Deacons' process: The method relied on hydrogen chloride being oxidized. In this method, chlorine is produced via the Deacon process.
4. Caster- Kellner process: In the 1890s, American Hamilton Caster and Austrian Karl Kellner developed the Caster-Kellner process, which electrolyzes an aqueous alkali chloride solution (often sodium chloride solution) to create the corresponding alkali hydroxide.

Final answer: Hence, the correct match is -

A. Sodium carbonate - Solvay

B. Titanium - Van-Arkel

C. Chlorine - Deacon

D. Sodium hydroxide - Caster-Kellner