Question

Which of the following is insoluble in aqueous NH3 solution?
Choose one:


AgCl


Pb(OH)2


Cu(OH)2


Zn(OH)2

Answer 1

Al(OH)3 is insoluble, because aqueous ammonia creates the conditions for it to precipitate. At lower pH it will be dissolved as Al3+.6H2O, at higher pH it will be dissolved as Al(OH)6(3-).