Read the following statements
i) Crystal of NaOH are deliquescent
ii) The by product formed in Solvay process is CaCl₂
iii) NaHCO₃ is a mild antiseptic for skin
infection 
 

• The substance which easily absorbs the moisture from the atmosphere are said to be deliquescent substances. High degree of hygroscopic nature of a substance is said to deliguescent
  Solvay process:
                         NH₄HCO₃ +NaCl$\to$NH₄Cl + NaHCO₃ 

                                 $2{\mathrm{NaHCO}}_3\stackrel{∆}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_3+{\mathrm{H}}_2\mathrm{O}$
The ammonia is regenerated by treating the by-product NH₄Cl with slaked lime [Ca(OH)₂]
                             2NH₄Cl + Ca(OH)₂ → 2NH₃ + CaCl₂ + 2H₂O
 NaHCO₃ is used as a mild antiseptic agent for skin infection.