Question

solubility of ionic compounds
classify each of the compounds as soluble or not soluble:
copper(ii) chloride
nickel(ii) sulfide
calcium iodide

Explanation:

Step1: Recall solubility rules for chlorides

Most chloride salts are soluble, and copper(II) chloride ($CuCl_2$) is no exception.

Step2: Recall solubility rules for sulfides

Most sulfide salts are insoluble, and nickel(II) sulfide ($NiS$) is insoluble.

Step3: Recall solubility rules for iodides

Most iodide salts are soluble, and calcium iodide ($CaI_2$) is soluble.

Answer:

copper(II) chloride: soluble
nickel(II) sulfide: not soluble
calcium iodide: soluble