I cannot seem to grasp the concept of how to write and solve half-reactions. Here are the questions:In lab you saw an electroplating demonstration involving a penny and a dime; both suspended in a copper sulfate solution.The copper was removed from the penny and plated onto the dime.Okay, so I know I‘ll use Cu and I‘m pretty sure Ag. a. Write the half-reactions for the electroplating demonstration. Reduction:Oxidation:b. Was this a spontaneous redox reaction? I‘m fairly certain that part B I do the cathode - anode to get the answer. If the answer is positive then it was spontaneous. I don‘t know which is the anode or cathode in the solution. Thank you.
The dime acts as the cathode because copper ions reduce onto it. Remember, the cathode is always where reduction occurs. oxidation reaction: Cu(s) --- Cu2+ + 2e- The copper from the penny loses electrons forming copper ions that go into the solution reduction reaction : Cu2+ + 2e- --- Cu(s) The copper ions in the solution gain electrons from the dime forming copper solid. Edit: you're right, there should be a 2 before the e. sorry. electroplating is done using an external power source, which means that the reaction is forced to occur and is therefore non-spontaneous.
