Question

Electroplating steel objects with silver involves a three-step process.

Step 1: A coating of copper is applied to the object.

Step 2: A coating of nickel is applied to the object.

Step 3: The coating of silver is applied to the object.

1. 1. A diagram of the apparatus used for step 1 is shown
      
      
      1. The chemical process taking place on the surface of the object is \[\ce{Cu^2+(aq) + 2e- ->Cu(s)}\]
         What is the observation seen on the surface of the object?
      2. Explain why the concentration of copper ions in the electrolyte remains constant throughout step 1.
2. Give two changes which would be needed in order to coat nickel on to the object in step 2.
3. Write down the reaction taking place at the positive electrode during step 3.

Answer 1

1. 1. reddish brown deposit/pink deposit/mass increases
   2. As anode released Copper ions the concentration of copper ions does not decrease
2. The anode should be made up of Nickel and the electrolyte should be aq. Nickel sulphate or any salt solution of Nickel
3. \[\ce{Ag -> Ag+ + e-}\]