Confused about the solubility of salts

Question

How many of the following salts are expected to be insoluble in water?

sodium sulfide - barium nitrate - ammonium sulfate - potassium phosphate

a.1

b.2

c.3

d.4

e.none

i am confused why is the answer soluble?

i thought sulfide are insoluble same with barium nitrate?

Answer 1

All nitrates are soluble, so not sure where you got the idea they are insoluble. Sulfides of transition metals are insoluble, but many group 1 sulfides (like Na2S) are soluble. All the others in the list are also soluble.

Answer 2

S^2- is insoluble except with Group IA, IIA and NH₄⁺ (sodium is a Group IA element). Therefore, sodium sulfide is soluble. All nitrate salts are soluble-no exceptions. Here is a solubility chart: it will help with the general rule and the exceptions. https://chemistryvce.weebly.com/uploads/8/9/7/4/89746771/solubility-table_orig.png