Copper (II) hydroxide is Cu(OH)2. It is also called cupric hydroxide. The Roman numeral II denotes the level of positive charge on the copper cation. Hydroxide (OH) always has a -1 charge, so the two of them are negated by the +2 charge on the copper to make a neutral compound. Copper as a transition metal can form two different cations, Cu+1 and Cu+2. The Roman numeral is used to distinguish between the two different possible cations. If we were talking about CuOH, then the chemical name would be copper (I) hydroxide to denote a +1 charge on the copper.