electroplating Flashcards
Why are objects electroplated?
- to protect the metal beneath from corroding
- to make the object look more attractive
- to increase the hardness of a surface and so its resistance to scratching
- to save money (and help with allergies)
How does electroplating an object save money?
Instead of using the pure expensive metal, a thin layer of a precious metal is used
How does electroplating help people’s allergies?
Nickel is a metal often used to make cheap jewellery, but people can be allergic to this. By electroplating the object with another metal, they do not have this problem
Why does it still make sense to electroplate large metal surfaces so to protect them from rusting and damage?
Even though this makes things expensive too, it can still make economic sense as they do not have to be replaced so often
What is the cathode in electroplating?
The metal object to be plated
What is the anode in electroplating?
This is made from the plating metal
Where does the electrolysis take place?
In a solution containing ions of the plating metal
In the experiment of nickel plating copper metal, what happens at the anode?
The nickel atoms in the electrode are oxidised. They lose two electrons and form nickel ions (Ni^2+) which leave the anode, and go into the solution
What is an electroplated object?
An object that has been coated with a thin layer of metal by electrolysis
What is the half equation at the anode when nickel plating an object?
Ni (s) ––> Ni^2+ (aq) + 2e^-
In the experiment of nickel plating copper metal, what happens at the cathode?
Nickel ions (Ni^2+) from the solution are reduced. They gain 2 electrons and form nickel atoms which are deposited on the metal cathode
What is the half equation at the cathode when nickel plating an object?
Ni^2+ (aq) + 2e^- ––> Ni (s)
What is used as the electrolyte in an electroplating form of electrolysis?
The metal being used to electroplate another metal in its form of ions, such as nickel sulfate or copper(II) sulfate solution
