By dissolving carbon dioxide with pure drinking water at a high pressure.
No, it is mostly prepared from brine (The saturated solution of NaCl) by electrolytic method.
Caustic soda means solid Sodium hydroxide NaOH, it is the 2nd most abundant synthetic chemical on earth also known as the 'Queen of the chemicals"
soda ash is mixed with slaked lime and heated, caustic soda and calcium carbonate is produced. This is regularly used in Paper & kraft mills.
Caustic Soda (Sodium hydroxide) can be found in Pharmacies/Drug stores such as Boots.
Sodium Hydroxide (NaOH) A powerful base often used in industries.