Electrochemistry question

In summary, spontaneous reduction occurs when the cell potential is positive, resulting in a negative change in free energy (ΔG). On the other hand, spontaneous oxidation occurs when the cell potential is negative, resulting in a positive change in free energy (ΔG). This means that spontaneous reduction can occur without any outside source driving the reaction, while spontaneous oxidation requires an outside source to drive the reaction. The relationship between cell potential and free energy is given by the equation ΔG = -nFE, where nF represents the total charge passed into or out of the cell and E is the cell potential.
  • #1
51
0
What is the different between spontaneous reduction and spontaneous oxidation? For spontaneous reduction you need to have Ecell to be (+), then what about spontaneous oxidation?

Thanks.
 
Physics news on Phys.org
  • #2
The work done on the cell / by the cell is given as,
ΔG = -nFE
Where nF is used to determined the total charge passed into / out of the cell and E is the cell potential.
If E is positive, ΔG is negative.
If E is negative, ΔG is positive.

The reaction is spontaneous (the cell does work) when ΔG is negative (E is positive).
The reaction needs to be driven by an outside source (work done on the cell) when ΔG is positive (E is negative).
 
  • #3


Spontaneous reduction and spontaneous oxidation are both important processes in electrochemistry that involve the transfer of electrons between different substances. The main difference between these two processes lies in the direction of the electron transfer.

In spontaneous reduction, electrons are gained by a substance, resulting in a decrease in its oxidation state. This process is considered spontaneous when the standard reduction potential (E°) of the reaction is positive, meaning that the reaction will occur spontaneously without the need for an external source of energy.

On the other hand, spontaneous oxidation involves the loss of electrons from a substance, resulting in an increase in its oxidation state. This process is considered spontaneous when the standard reduction potential is negative, indicating that the reaction will occur spontaneously without the need for an external source of energy.

In both cases, the standard reduction potential (E°) plays a crucial role in determining the spontaneity of the reaction. A positive E° value indicates that the reaction is thermodynamically favorable and will occur spontaneously, while a negative E° value indicates that the reaction will not occur spontaneously and an external source of energy is required.

In summary, the main difference between spontaneous reduction and spontaneous oxidation lies in the direction of electron transfer and the corresponding E° values that determine the spontaneity of the reaction.
 

1. What is electrochemistry?

Electrochemistry is the branch of chemistry that deals with the study of the relationship between electricity and chemical reactions.

2. What are some examples of electrochemistry in everyday life?

Some common examples of electrochemistry in everyday life include batteries, fuel cells, corrosion prevention, and electroplating.

3. How does an electrochemical reaction work?

An electrochemical reaction involves the transfer of electrons between two substances, typically a metal and a non-metal. The metal undergoes oxidation, losing electrons, while the non-metal undergoes reduction, gaining electrons.

4. What is the difference between a galvanic cell and an electrolytic cell?

A galvanic cell, also known as a voltaic cell, uses a spontaneous chemical reaction to generate electricity. An electrolytic cell, on the other hand, uses electricity to drive a non-spontaneous chemical reaction.

5. How is electrochemistry used in industry?

Electrochemistry plays a crucial role in many industries, such as in the production of metals, refining of oils, and in the manufacture of chemicals. It is also used in the development of new technologies, such as solar cells and fuel cells.

Suggested for: Electrochemistry question

Replies
1
Views
1K
Replies
6
Views
2K
Replies
1
Views
2K
Replies
2
Views
2K
Replies
4
Views
4K
Replies
4
Views
1K
Replies
2
Views
1K
Back
Top