Page 14 - Pharmaceutical analytical chemistry |

Amphoteric hydroxides:
Some hydroxides behave both as bases and acids under different
conditions, e.g., Zn(OH)2, Pb(OH)2, Al(OH)3, Cr(OH)3, Sb(OH)3,
Sn(OH)4
These hydroxides are only weakly basic, but like other bases, they still
combine with acids to form salt and water.

However in the presence of strong alkalis, these hydroxides behave like
acids, and combine with them to yield a salt and water.

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