Question

A student was given a solid containing a mixture of nitrate salts. The sample completely dissolved in water, and upon addition of dilute HCl, no precipitate formed. The pH was lowered to about 1 and H2S was bubbled through the solution. No precipitate formed. The pH was adjusted to 8 and H2S was again bubbled in. This time, a precipitate formed. Which compounds might have been present in the unknown?

Answer 1

What nitrates did you have? I assume you have list from which to choose. You could have
Ni, Co, Mn, Fe, Al, Cr, Zn

Answer 2

Na, Ca, Zn, Al, Mn

Answer 3

adw