Copper is plated on zinc by immersing a piece of zinc into a solution containing copper(II) ions. In the plating reaction, coppe
r II ions: a) gain two electrons and is are reduced. b) lose two electrons and is are oxidized. c) gain two electrons and is are oxidized. d)lose two electrons and is are reduced.
Copper plating on Zinc will occur via this simple reaction:
Cu²⁺ + 2 e⁻ ⇌ Cu
When a species gains electron, it is reduced. Its oxidation state is decreased. For example, in the above reaction Cu2+ gained 2 electron to get reduced to Cu. Its oxidation state changed from +2 to 0. Hence it is a reduction reaction.
So, the correct answer is :
The copper II ions gain two electrons and are reduced.
In order to solve this problem we need to <u>convert moles of carbon dioxide (CO₂) into moles of oxygen gas (O₂)</u>. To do so we'll use a conversion factor containing the <em>stoichiometric coefficients</em> of the balanced reaction: