Tag: Electrolytic cell

Introduction

One type of electrochemical cell is the electrolytic cell (EC), which converts electrical energy into chemical energy. This process causes an artificial redox reaction. Electrolytic cells may break down a wide variety of chemicals. It’s a technique for getting rid of ions in a mixture. The reduction half-cell and the oxidation half-cell together make up a single electrolytic cell. Energy for voltaic cells (VC) comes from a chemical reaction that happens naturally and results in a flow of electrons across a circuit (external). These cells are essential because they form the backbone of batteries, which provide the energy that runs modern civilization. Electricity is typically used to fuel non-spontaneous processes.

About Electrolytic Cell

It’s a device for electrolyzing a chemical compound, or breaking it down using an electric current. Simply put, this is a specific kind of electrochemical cell. Hydrogen (\({H_2}\)) and oxygen (\({O_2}\)) are produced when water is electrolyzed. Here, a bit of more power is required to get beyond the threshold energy level.

The electrolyte in these cells is often a fused or disintegrating ionic compound, and the cell itself consists of two electronic or metallic conductors (electrodes) that are either separated from one another or remain in touch with one another.

One of these is the use of a direct electric current source to link these electrodes, which keeps one of them negatively (-vely) charged while leaving the other, maybe positively (+vely), charged.

The cathode (-ve) moves the anode (+ve) and transfers one or more electrons to the cathode. This creates brand-new particles, either neutral or ions. Electron transmission is the determining factor in the cumulative effect of these two processes.

Galvanic Cell and Electrolytic Cell Comparison

Both electrolytic and galvanic cells function in the same way. There are three main features that make electrolytic cells and galvanic cells similar: Both cells need a salt bridge for proper functioning. Electrons (e-) always flow from the anode to the cathode, and both have cathode and anode components.

Difference Between Galvanic Cell and Electrolytic Cell

Electrolytic Cell Application

Some of the applications of electrolytic cell are

1. Generation of oxygen gas from water .
2. Electroplating
3. Electrorefining.
4. Electrowinning 
5. Isolation of metals of commercial importance such as aluminium, gold, copper, zinc, etc. 

Properties of Galvanic and Electrolytic Cells

Galvanic cells (GCs) are devices used to convert chemical energy into electrical energy. Electrolytic cells are capable of converting electrical energy into chemical energy. A salt bridge unites two segments housed in separate containers. The oxidation reaction takes place at the anode, and the redox reaction at the cathode. Electrons (e-) are supplied by an external cell and flow from the cathode to the anode.

Working Principle of an Electrolytic Cell

Electrolytic cells are instruments based on the idea that during an oxidation-reduction reaction, electrons (e-) are transferred from one chemical species to another.

Lets take the example of electrolysis of NaCl. 

Sodium metal and chlorine gas are produced during the decomposition of molten sodium chloride (NaCl).

Electrolysis occurs when a second energy source is applied to a vessel containing molten sodium chloride and carbon (C) electrodes. At the cathode end, the Na+ ion will be neutralised by the flow of electrons (e-) from the anode.

Although the anode and cathode retain their traditional roles, oxidation and reduction now occur at the cathode and anode, respectively. The electrolyte cell’s operational parameters are crucial to its proper functioning. Even the most potent reductant will succumb to oxidation. The most oxidising substance will be the one to be depleted.

The success of the Electrolytic Cell Molten sodium chloride (NaCl) depends on the electrolysis process, which is an integral part of the electrolytic cell.

Electrolysis of NaCl

Two non-active electrodes are submerged in a bath of liquid NaCl. Dissociated Na+ cations and Cl- anions are present here. The cathode is the part of the circuit where electrons (e-) gather when an electric current is sent through it. As a result, the resulting charge is negative (-ve). Because of this, the positively charged sodium (Na) cations go to the cathode, which is negatively charged. This results in the formation of sodium metal (Na) at the cathode.

Chlorine Cl atoms are transferred to the cathode during this process. It causes chlorine gas to be generated at the anode (Cl2). Two electrons (e-) are then freed, completing the circuit. In an electrolytic cell, molten NaCl is electrolyzed to produce Na and Cl2 gas, two metals (EC).

Summary

An electrolytic cell (EC) is a device that converts electrical energy into chemical energy via a non-spontaneous redox action. A reduction half-cell and an oxidation half-cell make them up. An electrolytic cell consists of the cathode, anode, and electrolyte. Similarities and differences exist between electrolytic cells and galvanic cells. As an example, the electron (e-) in each cell is unique. Understanding electrolysis requires familiarity with Faraday’s laws. The magnitudes of electrolytic effects are defined by them.

 

Frequently Asked Question

1. Define EMF?

Maximum potential difference between a cell’s electrodes is its electromotive force (EMF). The net voltage between the oxidation and reduction halves of a process is another way to think about it. The electromotive force (EMF) of a cell is the primary criterion for establishing the galvanic nature of an electrochemical cell.

2. What is the meaning of zero EMF in a battery?

After the chemical process within a battery is complete, the anode and cathode have the same number of electrons, and the electrical field between them is zero. When a reverse field is applied to a rechargeable battery’s contacts, the battery’s chemical makeup is returned to its previous state, allowing it to once again discharge electrons in an electrical circuit.

3. What is the relation between the current and the electrolytic product? 

The 1st law of Faraday says that the amount of electric current flowing through an electrolyte causes the same amount of chemicals to build up as the amount of current. Faraday’s law of electrolysis says that when the same amount of electric current flows through many electrolytes, the amount of materials that build up is proportional to their chemical equivalent.

Introduction

How does a mobile phone’s battery charge when plugged into its charger, or how does the cell in a TV remote control work? All of these questions have answers in the scientific field of electrochemistry. Electrochemistry is the study of both the use of electricity to conduct non-spontaneous chemical reactions and the production of electricity through chemical reactions. To achieve the goal, cells are used. Cells are components that initiate chemical reactions that produce or generate electricity.

What is an electrochemical reaction?

An electrochemical reaction is any process that is initiated or accompanied by the flow of electrical current, and typically involves the transport of electrons between two substances—one solid and one liquid. An electrochemical reaction occurs when a solid electrode and a material, such as an electrolyte, interact. This flow causes the reaction to release or absorb heat by producing an electric current to pass across the electrodes. When, for example, two electrodes in contact with one another initiate an oxidation and reduction (redox) reaction, the oxidation number of all the atoms involved in the reaction changes.

The process of electrochemical reaction

The properties of the negatively charged\(\;{e^ – }\)determine how matter interacts with an electric current as it flows through a system. Because protons are positively charged matter units found in elements, groups of atoms, or molecules, the electron, the fundamental unit of electricity, is drawn to them. This attraction is comparable to the chemical attraction that particles have for one another. Every chemical reaction changes the structure of an atom’s electrons, and the liberated electrons can either join with matter particles to form reductions or be ejected by them (oxidation). 

Faraday’s rules define the quantitative relationship between a free electron in a current flow and the atoms of a substance, where they cause a reaction. Electrochemical process components are also known as ionic conductors or electrolytes.

What is an Electrochemical cell?

An electrochemical cell is a system that can generate electrical energy from spontaneous chemical reactions. The chemical processes that occur during this process are known as redox reactions. During redox reactions, electrons are transferred between chemical species. They are also referred to as galvanic or voltaic cells. An electrochemical cell is illustrated by the Daniell cell.

The following are the essential components of an electrochemical cell:

1. An electrolyte is a substance found between electrodes that, when dissolved in polar solvents such as water, produces freely flowing ions, resulting in an electrically conducting solution.
2. Electrodes are solid electrical conductors that are used in electrochemical cells and are made of good conductors, such as metals.
3. They are available in two varieties:
4. The Cathode is the area of the cell where reduction takes place.
5. The anode is the part of the cell where oxidation takes place.
6. A salt bridge connects the oxidation and reduction halves of an electrochemical cell, completing the circuit. It is brimming with KCl and other saturated salt solutions. The bridge is required for the ions in the solution to flow between half-cells.

What are the different kinds of electrochemical cells?

There are two major kinds:

1. Galvanic Cell / Voltaic Cell: Chemical energy is converted to electrical energy in these electrochemical cells.
2. Electrolytic Cell: In these cells, electrical energy is converted to chemical energy.

Explain its operation

• Working Principle

The fundamental operating principle of an electrochemical system is the transfer of\(\;{e^ – }\)produced by a redox reaction occurring in it, which results in an electric current.

• Working Mechanism 

When the switch is turned on after an electrochemical cell has been fully assembled, the galvanometer of the external circuit deflects. The needle of the galvanometer moves in the direction of the beaker containing the copper sulphate solution. It indicates that the current has changed direction from the copper sulphate solution beaker to the zinc sulphate solution beaker. When the circuit is completed, a change occurs that causes zinc atoms in the zinc electrode to oxidise and Cu atoms in the copper rod to reduce. Zinc releases two electrons, which copper accepts via an external circuit.

Full redox reaction: \(\;Zn{\rm{ }}\left( s \right){\rm{ }} + {\rm{ }}C{u^{2 + }}\left( {aq} \right){\rm{ }} \to {\rm{ }}Z{n^{2 + }}\left( {aq} \right) + Cu{\rm{ }}\left( s \right)\;\;\;\)

Some applications of Electrochemical Cell

1. Many non-ferrous metals are electro-refined in metallurgy using electrolytic cells, yielding very pure metals such as Pb, Zn, Al, and Cu. 
2. It is used to recover pure Na metal from molten NaCl by storing it in an electrolytic cell.
3. Silver oxide batteries are used in hearing aids.
4. Thermal batteries are used in Navy gadgets for military applications.

Applications of Electrochemistry

1. Electrical batteries are created using the concept of cells. A battery is a device used in science and technology that stores chemical energy and provides electrical access to it.
   1. Applications in defence (thermal batteries)
   2. Digital cameras (Li batteries)
   3. Audio equipment (silver-oxide batteries)
2. Electroplating is used for a variety of purposes, including the production of jewellery and the corrosion protection of certain metals.
3. Electrochemistry is required in a variety of industries, including the chlor alkali industry.

Summary

Electrochemistry is a fascinating subject. Electrochemical reactions are important to comprehend because they have significant academic and practical implications. Understanding the responses allows us to better understand how everyday objects such as a battery or cell work. Chemical energy can be used to generate electrical energy in electrochemical cells, and electrical energy can be used to generate chemical energy.

Frequently Asked Questions 

1. What factors affect electrode potential?

Ans. The reduction potential refers to an electrode’s ability to accept electrons, whereas the oxidation potential refers to an electrode’s tendency to lose electrons. The potential of an electrode is determined by the temperature and metal ion concentration at its surface.

2. Can a zinc pot be used to store copper sulphate solution?

Ans. Copper has a lower reactivity than zinc. As a result, zinc can remove Cu from its salt solution. If the\(\;CuS{O_4}\) solution is kept in a zinc container, copper will be removed from the solution.

\[Zn + CuS{O_4} \to ZnS{O_4} + Cu\]

As a result, the copper sulphate solution cannot be stored in a zinc pot.

3. In the SI system, what is the emf measurement?

Ans. The energy contained in a battery per Coulomb of charge is known as the electromotive force, EMF has a SI unit of volts, which is equal to joules per coulomb.