An iron bar is to be electroplated with zinc. Draw a diagram to do so and:
-Identify what will act as the two electrodes for the cell
-identify each electrode as either the anode or cathode
-write the half-reactions occurring at each electrode
-identify a solution that would make a suitable electrolyte for this cell
-identify which electrode will be attached to the negative post of the battery and which will be attached to the positive post and explain.
-identify the flow of electrons
Can't draw a diagram/picture on this site. Take a beaker or vessel of some kind (vessel should not be a conductor of electricity and should not react with any of the contents). On the left side you will have a Zn bar dipping into an electrolyte, usually a special solution like methanesulfonic acid but less sophisticated ones in the lab can be found such as Na2SO4.
On the right you will have a Fe bar dipping into the same electrolyte solution.
You hook up a power supply with the + cable connected to the Zn bar and the - cable connected to the Fe bar. Turn on the power and the Zn goes into solution and becomes attached to the Fe bar. Post your work if this doesn't take care of all of the questions.
Electrolytic cell diagram of electroplate metal iron with zinc
To electroplate an iron bar with zinc, we will need the following components and steps:
1. Draw the diagram:
_________________
| |
Iron Bar | | Zinc Electrode
| |
-----------------
2. Identify the two electrodes for the cell: The iron bar and the zinc electrode will act as the two electrodes.
3. Identify which electrode is the anode and cathode:
- The iron bar will be the cathode (positive electrode).
- The zinc electrode will be the anode (negative electrode).
4. Write the half-reactions occurring at each electrode:
- At the cathode (iron bar): Fe2+ + 2e- -> Fe(s)
- At the anode (zinc electrode): Zn(s) -> Zn2+ + 2e-
5. Identify a suitable electrolyte solution for this cell: A suitable electrolyte for this cell would be a solution of zinc sulfate (ZnSO4), which contains Zn2+ ions.
6. Identify which electrode is attached to the negative and positive posts of the battery and explain:
- The iron bar (cathode) is attached to the negative post of the battery. This is because the negative terminal supplies the electrons needed for the reduction reaction (Fe2+ + 2e- -> Fe(s)) to occur at the cathode.
- The zinc electrode (anode) is attached to the positive post of the battery. This is because the positive terminal attracts the positively charged Zn2+ ions produced during the oxidation reaction (Zn(s) -> Zn2+ + 2e-) at the anode.
7. Identify the flow of electrons: Electrons flow from the iron bar (cathode) through the external circuit to the zinc electrode (anode).
To electroplate an iron bar with zinc, you will need the following setup:
1. Diagram:
___________________________
| |
| |
| ZnSO4 Solution |
| |
|___________________________|
| |
| |
| Iron Bar (Cathode) |
|___________________________|
| |
| |
| Zinc Electrode |
|___________________________|
2. Electrodes:
In this cell, the iron bar will act as the cathode, and the zinc electrode will act as the anode.
3. Half-reactions:
The half-reaction at the cathode (iron bar) involves the reduction of the metal ions from the electrolyte:
Fe^2+ + 2e^- → Fe (reduction)
The half-reaction at the anode (zinc electrode) involves the oxidation of the metal atoms:
Zn → Zn^2+ + 2e^- (oxidation)
4. Suitable electrolyte:
A suitable electrolyte for this cell is a solution of zinc sulfate (ZnSO4). This solution provides zinc ions (Zn^2+) needed for the redox reaction.
5. Battery connection:
The electrode connected to the negative post of the battery will be the zinc electrode (anode), while the iron bar (cathode) will be attached to the positive post. The reason for this is as follows:
- In an electrolytic cell, the cathode is connected to the positive terminal because it is where reduction occurs.
- The anode is connected to the negative terminal because it is where oxidation occurs, generating electrons that flow through the external circuit to the cathode.
6. Flow of Electrons:
In this electroplating process, electrons flow from the zinc electrode (anode) to the iron bar (cathode) through the external circuit. The zinc electrode undergoes oxidation, releasing electrons, and those electrons are then consumed during the reduction of iron ions at the cathode.