Pure copper(II) sulfate crystals may be prepared by reacting copper(II) oxide with hot dilute sulfuric acid. Copper(II) oxide is added until it ....1..... The mixture is ....2..... and then ....3..... so that the pure crystals are obtained. Which words fill gaps 1, 2 and 3?
- A1: is in excess, 2: cooled, 3: filtered
- B1: is in excess, 2: filtered, 3: cooled
- C1: changes colour, 2: cooled, 3: filtered
- D1: changes colour, 2: filtered, 3: cooled