21 Facts About Chemical reactions

Chemical reactions reaction is a process that leads to the chemical transformation of one set of chemical substances to another.

Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei, and can often be described by a chemical equation.

Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants.

Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions.

Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration.

Different chemical reactions are used during chemical synthesis in order to obtain a desired product.

Such Chemical reactions require the addition of energy in the form of heat or light.

In redox Chemical reactions, the transferred particle is an electron, whereas in acid–base Chemical reactions it is a proton.

The forward and reverse Chemical reactions are competing with each other and differ in reaction rates.

Typical examples of exothermic Chemical reactions are combustion, precipitation and crystallization, in which ordered solids are formed from disordered gaseous or liquid phases.

Redox Chemical reactions can be understood in terms of transfer of electrons from one involved species to another .

In practice, the transfer of electrons will always change the oxidation state, but there are many Chemical reactions that are classed as "redox" even though no electron transfer occurs .

An important class of redox reactions are the electrolytic electrochemical reactions, where electrons from the power supply at the negative electrode are used as the reducing agent, and electron withdrawal at the positive electrode as the oxidizing agent.

Complexation Chemical reactions include ligand exchange, in which one or more ligands are replaced by another, and redox processes which change the oxidation state of the central metal atom.

Acid–base Chemical reactions can have different definitions depending on the acid–base concept employed.

However, because of the relatively small diffusion rates in solids, the corresponding chemical reactions are very slow in comparison to liquid and gas phase reactions.

Similar to the substitution Chemical reactions, there are several types of additions distinguished by the type of the attacking particle.

The [4+2] Diels-Alder Chemical reactions can be assisted by heat whereas the [2+2] cycloaddition is selectively induced by light.

Biochemical reactions that occur in living organisms are collectively known as metabolism.

Chemical reactions are central to chemical engineering, where they are used for the synthesis of new compounds from natural raw materials such as petroleum, mineral ores, and oxygen in air.

Faster Chemical reactions are usually studied with ultrafast laser spectroscopy where utilization of femtosecond lasers allows short-lived transition states to be monitored at time scaled down to a few femtoseconds.