Potassium chloride
Iron (II) chloride
Copper (II) sulfate
Aluminum oxide
Iron (III) oxide
Remember to put roman numerals for the compounds where the metal has more than one possible oxidation state. For example, you see iron here with a +2 charge in one compound and then +3 charge in another. If the metal only has one possible oxidation state (like potassium and aluminum), you don't need a roman numeral.