What Is Electric In Chemistry?

Electricity is the flow of electrons or electrically charged particles. It is produced by the movement of charged particles, usually electrons, through a conductive medium like wires, circuits, or even liquids and gases. In chemistry, electricity is used in a variety of applications and processes.

Electric current refers specifically to the flow of electric charge carriers like electrons. Electric current is measured in amperes and flows from areas of high potential to low potential in a circuit. Harnessing electric current is a crucial part of electrochemistry.

Electricity plays several important roles in chemistry. At its most basic level, it allows chemists to power equipment like stirrers, heaters, and spectroscopes in the lab. Electricity enables electrochemical reactions and processes like electrolysis, electrophoresis, electroplating, and the operation of electrochemical cells like batteries and fuel cells. Sensors that measure chemical properties can transduce signals electrically. Electricity even plays a role in emerging fields like organic electronics and electroceuticals.

Electric Force and Charge

Electric force is the force between charged particles. Positively charged particles repel other positively charged particles but attract negatively charged particles. Negatively charged particles repel other negatively charged particles but attract positively charged particles. The strength of the electric force depends on the magnitude of the charges and the distance between them.

Electric charge is a fundamental property of matter that causes particles to experience electric forces. There are two types of electric charge: positive and negative. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. Atoms are overall neutral but can gain or lose electrons to become charged ions.

When an atom loses electrons it becomes a positively charged cation. Some examples of cations include sodium, potassium, calcium. When an atom gains electrons it becomes a negatively charged anion. Some examples of anions include chloride, fluoride, hydroxide.

Electrochemical Cells

Electrochemical cells convert chemical energy into electrical energy through oxidation-reduction reactions. They consist of two half-cells, each containing an electrode immersed in an electrolyte solution. The electrodes are made of different metals or compounds that have different tendencies to lose or gain electrons. One electrode gives up electrons (becomes oxidized) while the other electrode gains electrons (becomes reduced). This flow of electrons between the electrodes generates an electric current that can do work.

The most common electrochemical cell is the voltaic cell, also known as a galvanic cell. It uses spontaneous redox reactions to generate electricity. The cell consists of two half-cells connected by a salt bridge and external circuit. The anode is the electrode where oxidation occurs and electrons flow out of the cell into the external circuit. The cathode is where reduction occurs and electrons flow into the cell from the external circuit. As electrons move through the external circuit, they provide power to do work. Some common examples of voltaic cells are copper-zinc batteries, alkaline batteries, and lead-acid car batteries.

Another type of electrochemical cell is the electrolytic cell. It uses electricity to drive a non-spontaneous redox reaction. Electrolytic cells convert electrical energy into chemical energy and are used for processes like electroplating and electrorefining metals. They consist of two electrodes connected to an external power source that supplies electrons to drive the redox reaction. Common examples are cells used in the industrial production of metals like aluminum and sodium.

Electrolysis

Electrolysis is a technique that uses direct electric current to drive an otherwise non-spontaneous chemical reaction. In electrolysis, electrodes in an electrolytic cell are connected to an external power source, like a battery. When voltage is applied, the positive ions, called cations, migrate to the negatively charged cathode. The negative ions, called anions, migrate to the positively charged anode. At the electrodes, the ions are either reduced or oxidized.

A simple example of electrolysis is the decomposition of water into hydrogen and oxygen gas. Water molecules (H2O) are split into hydrogen ions (H+) and hydroxide ions (OH-) when an electric current is passed through them. At the cathode, the hydrogen ions gain electrons and are reduced to hydrogen gas (H2). At the anode, the hydroxide ions lose electrons and are oxidized to oxygen gas (O2).

Other examples of electrolysis include extracting reactive metals like sodium, potassium and aluminum from molten salts or ores using large electric currents. Electrolysis is also used commercially for electroplating and electrorefining metals.

Electrophoresis

Electrophoresis is a technique used to separate charged molecules based on their size and charge. It works by applying an electric field to a gel matrix or microfluidic channel. Charged molecules will then move through the matrix at different speeds based on their size and charge.

Smaller molecules move faster through the gel while larger molecules move slower. At the same time, positively charged molecules move towards the negative electrode while negatively charged molecules move towards the positive electrode. By optimizing the gel concentration, pH, electric field strength, and length of time allowed for separation, molecules can be separated with high resolution based on size.

Examples of electrophoresis use include DNA electrophoresis for DNA fingerprinting and sequencing, protein electrophoresis for analyzing protein composition, and agarose gel electrophoresis for separating fragments of DNA and RNA. Electrophoresis is a standard procedure in molecular biology labs and has many applications in forensics, genetic testing, molecular biology research, and clinical diagnostics.

Electroplating

Electroplating is a process that uses an electric current to coat a conductive surface with a thin layer of metal. The surface to be plated, called the substrate, serves as the cathode (negative electrode) in the electrochemical cell, and the metal to be deposited serves as the anode (positive electrode).

The substrate and anode are immersed in a solution that contains ions of the metal to be deposited. When an electric current is applied, the metal ions in the solution are attracted to the cathode and reduced onto its surface. This forms a uniform and adherent coating of the metal over the substrate.

Some common uses of electroplating in industry and science include:

• Coating metal objects with a thin layer of a different metal for protection against corrosion and wear
• Applying decorative and aesthetic metal coatings to objects
• Electrically insulating or soldering metal components
• Adjusting the frictional properties of metal parts
• Building up worn or undersized metal parts to original dimensions
• Applying uniform metal coatings to irregularly shaped objects
• Producing very pure metals for research purposes

Overall, electroplating allows controlled and precise application of metal coatings for a wide variety of purposes across many industries.

Electrochemical Sensors

Electrochemical sensors are devices that use electrochemical reactions to detect and measure the presence or concentration of certain chemicals. They work by converting the chemical information into an electrical signal that can be easily measured and analyzed.

The basic components of an electrochemical sensor include a working electrode, a reference electrode, and an electrolyte solution. The analyte being measured undergoes oxidation or reduction reactions at the working electrode, generating or consuming electrons. This creates a current that correlates to the analyte concentration. The reference electrode provides a fixed potential to control the reactions occurring at the working electrode.

Some common applications of electrochemical sensors include:

• Blood glucose monitors – Measure glucose levels using enzyme-coated electrodes.
• Breathalyzers – Detect blood alcohol content by oxidizing ethanol.
• Gas leak detectors – Detect combustible gases like methane using catalyzed electrodes.
• Water quality tests – Measure heavy metals, pH, and contaminants in water samples.
• Neurochemical monitoring – Detect neurotransmitters and hormones in the brain.

Electrochemical sensors are widely used due to their high sensitivity, low cost, simplicity of design and ability to be miniaturized. Advances in nanomaterials and microfabrication have enabled further improvements in the performance and portability of electrochemical sensors.

Batteries

Batteries are electrochemical devices that convert chemical energy into electrical energy. They rely on redox reactions, where electrons are transferred between chemical species. This process occurs spontaneously, allowing the battery to generate electricity.

Inside a battery, there are two electrodes – the anode and the cathode. These are made of different materials and are separated by an electrolyte. The electrolyte allows ions, but not electrons, to flow between the electrodes.

When the circuit is closed, oxidation reactions occur at the anode, generating electrons. These electrons flow through the external circuit to the cathode. At the cathode, reduction reactions occur, consuming the electrons. The ions flow through the electrolyte to balance the charge.

Some common battery types include:

• Lead-acid batteries – Used in vehicles. The anode is lead, the cathode is lead dioxide, and the electrolyte is sulfuric acid.
• Alkaline batteries – Used in flashlights and other household devices. The anode is zinc, the cathode is manganese dioxide, and the electrolyte is potassium hydroxide.
• Lithium-ion batteries – Used in consumer electronics and electric vehicles. The anode is carbon, the cathode is a lithiated metal oxide, and the electrolyte is a lithium salt in an organic solvent.

Organic Conductors

Organic molecules and polymers can also exhibit electrical conductivity. This is due to the presence of extensive conjugated π-bonding systems that allow charge carriers to move along the molecule. Conjugated systems contain alternating single and double bonds, creating an overlap of p-orbitals that allows electrons to flow. Examples of conductive organic molecules include polyacetylene, polythiophene, polyaniline, and polypyrrole.

The discovery of conductive polymers has opened up various technological applications. Organic conductors are lightweight, flexible, and easy to tune by molecular modifications. They are used in antistatic coatings, electronic textiles, printed circuit boards, organic solar cells, organic light-emitting diodes, and electrochromic displays. Conductive polymers can also be integrated with biological systems for biosensors and neural interfaces. The tunability and processability of organic conductors provide them with advantages over inorganic materials in certain applications.

Future Applications

The future of electrochemistry shows great promise as scientists continue to develop innovative technologies and applications. Here are some potential advancements on the horizon:

Implantable biofuel cells – Miniaturized biofuel cells could be implanted in the body to power medical devices or provide electricity to muscles or organs. Enzymes would catalyze reactions using glucose or other biological fuels to generate an electrical current.

Improved batteries – Advances in battery chemistry, nanomaterials, and battery architecture could lead to major performance gains like faster charging times, higher capacity, and longer lifetimes.

Electrochemical water treatment – Electrocoagulation and electrooxidation processes may offer solutions for water purification, desalination, and industrial wastewater treatment.

Neuroprosthetics – Electrodes implanted in the brain could restore sensory functions, allow control of prosthetic limbs, restore movement after paralysis or enable telepathic communication.

Electrochromic displays – Flexible electrochromic displays could mimic color changing abilities seen in animals like chameleons and octopuses for adaptive camouflage or signaling.

As we gain greater mastery of electrochemical systems at the nano and molecular scale, researchers will uncover exciting new ways that electricity can enhance and extend human capabilities.