Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 5. Compounds of Common Use
Properties of Sodium Hydroxide
12. Properties of Sodium Hydroxide. (i) It is deliquescent solid and absorbs moisture and CO2, finally forming solid hydrated carbonate. (ii) It can precipitate cations like Zn2+, Al3+, Pb2+, Sn2+ but these precipitates get dissolved in excess of NaOH. Zn(OH)2 + 2OH– → [Zn(OH)4]2– (Zincate Ion) Al(OH)3 + 3OH– → [Al(OH)6]3– (Aluminate Ion) Sn(OH)2 + 4OH– → [Sn(OH)6]3– (Stannate Ion) Pb(OH)2 + 2OH– → [Pb(OH)4]2– (Plumbate Ion) 13. Uses of Sodium Hydroxide. (i) It is used in soap industry. (ii) It is used in paper industry (iii) It is used in textile industry (iv) It is used for preparation of pure fats and oils. (v) It is used in preparation of artificial silk (rayon). (vi) It is used in petroleum industry. (vii) It is used in absorbing poisonous gases. (viii) It is used as reagent in laboratory.