Cell Reactions

Cell reactions describe the entire chemical change in a simplified manner. Its reaction equation can be defined as the sum of two electrode reactants equations with the cancellation of electrons. In this article, we will be discussing cell reactions, electrolytic cell, cathode, anode and their differences in detail. 

What are Cell Reactions? 

A cell reaction can be defined as the overall reaction in a cell. It is based on assumptions that the right-hand side electrode is the cathode, whereas the left-hand side electrode is the anode. To write the cell reaction corresponding to a cell diagram, the left-hand half reaction is mentioned as oxidation, whereas the right-hand half reaction is given as reduction. Therefore, the cell reaction for the Cu2+/Cu and Fe3+/Fe2+ cell is given as – 

2Fe3+(aq) + Cu (s) → 2Fe2+(aq) + Cu2+(aq)

Electrode Reaction and Cell Reactions 

A cell diagram having its designation of the right and left electrodes allows writing cell reaction equations. These equations are given so that electrons enter the right terminal and leave at the left one. At each electrode, an electrode reaction takes place. The cell reaction is responsible for describing the entire chemical change. If we write a cell’s electrode reaction. It will be given as – 

oxidation at left: H2 (g)→2H+ (aq)+2e-

reduction at right: 2 AgCl(s)+2e− →2Ag(s)+2Cl−(aq)

As mentioned above, the stoichiometric numbers in both electrons have the same absolute value, which is allowing the 2 electron to cancel when adding the electrode reactions to form the cell reaction – 

H2(g) + 2AgCl(s)→2H+(aq) + 2Cl− (aq)+2Ag(s)

What is an Electrolytic Cell? 

An electrolytic cell is termed an electrochemical device that tends to use electrical energy for facilitating the non-spontaneous redox reaction. The electrolytic cells are often termed electrochemical cells, which are mostly used for the electrolysis of certain compounds. 

Primarily, there are three components of electrolytic cells. These are as follows- 

1. Cathode
2. Anode
3. Electrolyte

The electrolyte provides a common medium for exchanging electrons between the anode and cathode. 

Comparison Between Galvanic Cells and Electrolytic Cells- 

What is Cathode?

The cathode in chemistry is an important term. It can be defined as the electrode where reduction takes place. It is extremely common when we talk about electrochemical cells. Since the energy supplied to the cell leads to the decomposition of chemical compounds, the cathode is negative. However, in the case of the galvanic cell, the cathode can be positive as the chemical reaction leads to electrical energy generation. 

Additionally, a cathode can be termed a cold cathode or hot cathode. The hot cathode is referred to as a cathode that is heated in the filament presence for emitting electrons by thermionic emission. However, the cold cathode is simply not heated by any filament. Generally, a cathode is cold. 

What is an Anode? 

In most simple terms, an anode in electrochemistry can be referred to as the point when an oxidation reaction occurs. Generally, at an anode, negative anions or ions tend to reach and give up electrons because of their unparalleled electrical potential. When talking about the galvanic cell, it is negatively charged as the electrons tend to move outside the electric circuit. On the other hand, it is positive in the electrolyte cell. 

Difference Between a Cathode and Anode 

Here are the differences between a cathode and anode: