Copper can be used for water pipes in homes. When the pipes corrode, copper atoms oxidize to form Cu²⁺ ions in the water. A homeowner has a water quality report prepared for a sample of water taken from pipes in the home. According to the report, the 550.-gram sample contains 6.75 x 10⁴ gram of dissolved Cu²⁺ ions.

79 Using the key in your answer booklet, draw two water molecules in the box, showing the orientation of each water molecule toward the Cu²⁺ion. [1]

Link to the Answer for 79

80 Show a numerical setup for calculating the concentration, in parts per million, of dissolved Cu²⁺ ions in the sample of water tested. [1]

81 Write a balanced half-reaction equation for the corrosion that forms the Cu2 ions. [1]