The mass was recorded and transferred to a 50 ml beaker. 4 ml of 6 M HNO3 was added to the beaker containing the copper. For step 2, 10 ml of distilled water was added to the beaker. Then, 6 M NaOH was added to the solution (drop wise), until placing a drop of the solution on red litmus paper turned it blue. For step 3, the solution was heated with a hot plate.