Using the solubility chart below, identify the cations that would be expected to form a precipitate upon initial addition of sulfate (i.e. SO₄ ^2- OR S O4 2 minus)

Solubility Table

Header Row

Ion Solubility Exceptions

Table Body arranged in rows

N O 3 minus soluble none

C l minus soluble except A g+, H g2 2+, *Pb2+

I minus soluble except A g+, H g2 2+, *Pb2+

S O4 2minus soluble except C a 2+, B a2+, S r2+, H g2+, P b2+, A g+

C O3 2minus insoluble except Group IA and NH4+

P O 4 3 minus insoluble except Group IA and NH4+

O H minus insoluble except Group IA, *C a 2+, B a 2+, S r 2+

S 2 minus insoluble except Group IA, IIA and NH4 1+

N a+ soluble none

K+ soluble none

NH4 1+ soluble none

*= partially soluble

End Table

• Pb2+
• C a 2+
• A g+
• B a 2+

Using the table below from http://www.docbrown.info/page07/appendixtrans12.htm

match the cations with the color of the precipitate that it will form INITIALLY when treated with hydroxide. NOTE : More than one might have the same color.

• Ni2+
• Al3+
• Cr3+
• Fe3+
• Cu2+
• Zn2+

1. green gel

2. brown gel

3. blue gel

4. white gel

__1__ Ni2+

__4__ Al3+

__1__ Cr3+

__2__ Fe3+

__3__ Cu2+

__4__ Zn2+