Im having trouble on a question Im not sure what it is they are asking for.
A voltaic cell similar to that shown in Figure 20.5 is constructed. One electrode compartment consists of a silver strip placed in a solution of AgNO3, and the other has a iron strip placed in a solution of FeCl2. The overall cell reaction is given below.
2 Ag+(aq) + Fe(s) 2 Ag(s) + Fe2+(aq)
a)Which electrode is the anode, and which is the cathode.
anode
wouldn't the Ag be the anode because it is losing electrons and the Fe be the cathode???
The Ag electrode gains electrons doesn't it. Ag^+ + e ==> Ag
You may be confusing yourself because you have no arrow to show the products versus the reactants. ALWAYS place an arrow in an equation. It isn't an equation without one.
oh ok i see! thanks!
i have a follow up question:
In which directions do the cations and anions migrate through the solution?
toward the silver cathode ? or
toward the iron cathode ?
so do the anions(Fe)migrate to the silver? and cations toward the iron? there is a diagram that goes along with this and im not sure if you need to look at it to solve this problem
The Fe electrode is the anode and negatively charged. The Ag electrode is the cathode and positively charged. I would like to see the diagram but there is no way to do that.
This diagram may help. Note the direction of the K^+ and the NO3^- from the KNO3 salt bridge.
http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Voltaic_Cells
To determine which electrode is the anode and which is the cathode in the given voltaic cell, you need to understand the concept of redox reactions and the flow of electrons.
In a redox reaction, the species that undergoes oxidation loses electrons, while the species that undergoes reduction gains electrons. The anode is the electrode where oxidation occurs, while the cathode is the electrode where reduction occurs.
Looking at the given cell reaction:
2 Ag+(aq) + Fe(s) → 2 Ag(s) + Fe2+(aq)
In this reaction, silver ions (Ag+) are being reduced to form solid silver (Ag), while iron (Fe) is being oxidized to form iron ions (Fe2+).
So, the species that is being oxidized is Fe, and the one being reduced is Ag+. Therefore, Fe is the anode, and Ag is the cathode.
To summarize:
- Anode: Fe electrode (where Fe(s) is located)
- Cathode: Ag electrode (where Ag(s) is located)
Remember, in a cell reaction, the anode is where oxidation occurs (losing electrons), and the cathode is where reduction occurs (gaining electrons).