identify the 2 substances whose aqueous solutions have common properties to a marked degree and explain your answer.

a) CuS, CuCI2, Na2 S, KCI

b) HCI, HC2H3O2, NH4C2H3O2

Amber, I don't get it.

a) could be CuS/CuCl2 because both contain the Cu atom OR
CuCl2/Na2S are soluble OR
KCl/CuCl2 both contain the Chloride ion. etc.