# How much electrical energy can be extracted from Iron in a cell?

• Kisen
In summary, the cell produces 1.21 volts before becoming balanced. If the cells are not balanced, then the cell will stop working due to identical potentials.

#### Kisen

TL;DR Summary
How much electrical energy can be extracted from Iron in a cell?
Hi,
I am trying to get to an answer for the following scenario.

Imagine you have an electrochemical cell in its most basic terms.
On the negative electrode you have 3 moles of iron metal in a chloride solution. On the positive side you have 3 moles FeCl3 solution. These are separated by a membrane. A pretty standard setup.

When you connect a load between the positive and negative electrodes, electrons flow as iron metal oxidises to Fe2 and Fe3 reduces to Fe2.

What i am trying to calculate is how much energy does the above setup produce before the cell becomes balanced?
If not balanced, then what's left over after one of the electrodes reaches a state of all Fe2?

Can you write reactions for both cells? Can you write Nernst equation for both cells? Battery will stop working when these potentials are identical.

• Lord Jestocost
Borek said:
Can you write reactions for both cells? Can you write Nernst equation for both cells? Battery will stop working when these potentials are identical.
Hi,
Here are the reactions during discharge for both side of the cell. I don't know what a Nernst equation is. Will a Nernst equation help me to calculate how much overall energy is in a cell of a given size?

Reactions:

Positive electrode: 2FeCl3 + 2e- -> 2FeCl2 + 2Cl- Eo = 0.77V

Negative electrode: Fe + 2Cl- -> FeCl2 + 2e- Eo = -0.44V

Overall cell reaction: Fe + 2 FeCl3 -> 3FeCl2 Eocell = 1.21V

Nernst equation let's you calculate the potential as a function of concentration of ions involved, so it will let you calculate the final potential. It will also let you calculate all intermediate potentials as a function of the reaction progress towards the equilibrium, as concentrations are rather simple function of the reaction stoichiometry - which is in turn easy to combine with the flowing current or charge transfer (through the Faraday's law of electrolysis). VI is power, integrate it from the initial concentration to the equilibrium and you have energy of the system.

It is also definitely possible to calculate the amount of energy from thermodynamics, using Gibbs energy of the system. In theory I should be able to do that, in practice I forgot too much and I prefer to not risk making an idiot out of myself ## 1. How does electrical energy extraction from Iron in a cell work?

The process of extracting electrical energy from Iron in a cell involves converting the chemical energy stored in the bonds of Iron to electrical energy through a series of chemical reactions. This process, known as redox reaction, involves the transfer of electrons from Iron to an electron acceptor, such as oxygen or hydrogen ions, which creates an electrical current.

## 2. How much electrical energy can be extracted from a single Iron cell?

The amount of electrical energy that can be extracted from a single Iron cell depends on various factors such as the amount of Iron present, the efficiency of the redox reaction, and the capacity of the electron acceptor. However, on average, a single Iron cell can produce around 0.4 volts of electrical energy.

## 3. Can Iron cells be used as a reliable source of electrical energy?

While Iron cells can produce electrical energy, they are not considered a reliable source of energy due to their low efficiency and limited capacity. Iron cells also require a constant supply of Iron and an electron acceptor, making them less practical for long-term use compared to other sources of electrical energy, such as batteries or fuel cells.

## 4. Is extracting electrical energy from Iron in a cell environmentally friendly?

The process of extracting electrical energy from Iron in a cell is generally considered environmentally friendly because it does not produce any harmful byproducts or emissions. However, the mining and production of Iron can have negative environmental impacts, making it important to consider the source and production methods of Iron cells.

## 5. Are there any potential applications for using Iron cells to extract electrical energy?

While Iron cells may not be a practical source of electrical energy, they have potential applications in biotechnology and bioengineering. For example, Iron cells can be used to power microdevices or sensors within the human body, providing a sustainable and renewable source of energy for medical purposes.