caustic soda

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caustic soda (sodium hydroxide, NaOH) Strong alkali prepared industrially by the electrolysis of salt (sodium chloride, NaCl). It is a white solid that burns skin, with a slippery feel because it absorbs moisture from the air. It also absorbs atmospheric carbon dioxide, forming a crust of sodium carbonate (Na2CO3). Caustic soda is used in many industries, such as soapmaking and in bauxite-processing to make aluminium.