A single-displacement reaction, also known as single replacement reaction or exchange reaction, is an archaic concept in chemistry. It describes the stoichiometry of some chemical reactions in which one element or ligand is replaced by atom or group. [1] [2] [3]
It can be represented generically as:
where either
This will most often occur if is more reactive than , thus giving a more stable product. The reaction in that case is exergonic and spontaneous.
In the first case, when and are metals, and are usually aqueous compounds (or very rarely in a molten state) and is a spectator ion (i.e. remains unchanged). [1]
In the reactivity series, the metals with the highest propensity to donate their electrons to react are listed first, followed by less reactive ones. Therefore, a metal higher on the list can displace anything below it. Here is a condensed version of the same: [1]
Similarly, the halogens with the highest propensity to acquire electrons are the most reactive. The activity series for halogens is: [1] [2] [3]
Due to the free state nature of and , single displacement reactions are also redox reactions, involving the transfer of electrons from one reactant to another. [4] When and are metals, is always oxidized and is always reduced. Since halogens prefer to gain electrons, is reduced (from to ) and is oxidized (from to ).
Here one cation replaces another:
(Element A has replaced B in compound BC to become a new compound AC and the free element B.)
Some examples are:
These reactions are exothermic and the rise in temperature is usually in the order of the reactivity of the different metals. [5]
If the reactant in elemental form is not the more reactive metal, then no reaction will occur. Some examples of this would be the reverse.
External videos | |
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CuCl2 and Iron Part 2, 2011 | |
Reaction of CuCl2 with Al, 2011 | |
Copper Sulfate and Iron: Part 1, 2011 |
Here one anion replaces another:
(Element A has replaced B in the compound CB to form a new compound CA and the free element B.)
Some examples are:
Again, the less reactive halogen cannot replace the more reactive halogen:
Metals react with acids to form salts and hydrogen gas.
However less reactive metals can not displace the hydrogen from acids. [3] (They may react with oxidizing acids though.)
Metals react with water to form metal oxides and hydrogen gas. The metal oxides further dissolve in water to form alkalies.
The reaction can be extremely violent with alkali metals as the hydrogen gas catches fire. [2]
Metals like gold and silver, which are below hydrogen in the reactivity series, do not react with water.
External videos | |
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Reaction of Potassium and Water, 2011 | |
Reaction of Magnesium and Water, 2011 |
Coke or more reactive metals are used to reduce metals by carbon from their metal oxides, [6] such as in the carbothermic reaction of zinc oxide (zincite) to produce zinc metal:
and the use of aluminium to produce manganese from manganese dioxide:
Such reactions are also used in extraction of boron, silicon, titanium and tungsten.
Using highly reactive metals as reducing agents leads to exothermic reactions that melt the metal produced. This is used for welding railway tracks. [6]
a(Haematite)
Silver tarnishes due to the presence of hydrogen sulfide, leading to formation of silver sulfide. [7] [2]
Chlorine is manufactured industrially by the Deacon's process. The reaction takes place at about 400 to 450 °C in the presence of a variety of catalysts such as .
Bromine and iodine are extracted from brine by displacing with chlorine.
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH via titration. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.
Sulfuric acid or sulphuric acid, known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is miscible with water.
In chemistry, a half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction. Often, the concept of half reactions is used to describe what occurs in an electrochemical cell, such as a Galvanic cell battery. Half reactions can be written to describe both the metal undergoing oxidation and the metal undergoing reduction.
Aqua regia is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3. Aqua regia is a fuming liquid. Freshly prepared aqua regia is colorless, but it turns yellow, orange or red within seconds from the formation of nitrosyl chloride and nitrogen dioxide. It was named by alchemists because it can dissolve noble metals like gold and platinum, though not all metals.
In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used.
Silane (Silicane) is an inorganic compound with chemical formula SiH4. It is a colourless, pyrophoric, toxic gas with a sharp, repulsive, pungent smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Silane with alkyl groups are effective water repellents for mineral surfaces such as concrete and masonry. Silanes with both organic and inorganic attachments are used as coupling agents. They are commonly used to apply coatings to surfaces or as an adhesion promoter.
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas. The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction. The chemical formulas may be symbolic, structural, or intermixed. The coefficients next to the symbols and formulas of entities are the absolute values of the stoichiometric numbers. The first chemical equation was diagrammed by Jean Beguin in 1615.
In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.
In chemistry, a reactivity series (or reactivity series of elements) is an empirical, calculated, and structurally analytical progression of a series of metals, arranged by their "reactivity" from highest to lowest. It is used to summarize information about the reactions of metals with acids and water, single displacement reactions and the extraction of metals from their ores.
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In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
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Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH3 and phenylmagnesium bromide (C6H5)−Mg−Br. They are a subclass of the organomagnesium compounds.
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical.
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This list gives an overview of the classification of non-silicate minerals and includes mostly International Mineralogical Association (IMA) recognized minerals and its groupings. This list complements the List of minerals recognized by the International Mineralogical Association series of articles and List of minerals. Rocks, ores, mineral mixtures, not IMA approved minerals, not named minerals are mostly excluded. Mostly major groups only, or groupings used by New Dana Classification and Mindat.
Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. A few metal halides are discrete molecules, such as uranium hexafluoride, but most adopt polymeric structures, such as palladium chloride.
Chlorine-free germanium processing are methods of germanium activation to form useful germanium precursors in a more energy efficient and environmentally friendly way compared to traditional synthetic routes. Germanium tetrachloride is a valuable intermediate for the synthesis of many germanium complexes. Normal synthesis of it involves an energy-intensive dehydration of germanium oxide, , with hydrogen chloride, Due to the environmental and safety impact of non-recyclable, high energy reactions with , an alternative synthesis of a shelf-stable germanium intermediate precursor without chlorine is of interest. In 2017, a synthesis of organogermanes, without using chloride species was reported, allowing for a much more environmentally friendly and low energy synthesis using , , and even selectively activating germanium in the presence of zinc oxide, resulting in products that are bench stable and solid.
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