Which if the following compounds is insoluble in water

(NH4)2CO3
AgBr
CuSO4
KI
LiNO3

is it CuSO4 because sulfates are insolube

2 answers

Use that solubility chart.
Here is rule 4 of the solubility rules I posted yesterday and today. Note that copper is not listed as an exception; therfore, CuSO4 is soluble.

All sulfates are soluble, except those of barium, strontium, calcium, lead, silver, and mercury (I). The latter three are slightly soluble.