Question

Which of the following ionic compounds are soluble in water?

Potassium perchlorate
Lithium phosphate
Lead nitrate
Barium perchlorate
Lead iodide

Answer 1

KClO4 (solubility is about 1.5 g/100 g) so some may consider this insoluble but I don't. KClO4 is the least soluble of the perchlorates.
Li3PO4
Pb(NO3)2
Ba(ClO4)2
PbI2 is insoluble.