These compounds share features with both the inert interstitials and the more reactive salt-like carbides. Metal complexes containing C n fragments are well known. These molecular carbides often have carbon-centered clusters. Some metals such as tin and lead are not believed to form carbides. Oxocarbons are compounds containing carbon and oxygen; they exist as carbon oxides and carbonates.
Carbon oxides, or oxocarbons, are a class of organic compounds containing only carbon and oxygen. The most basic oxocarbons are carbon monoxide and carbon dioxide. Many other stable and metastable oxides of carbon are known but are rarely encountered. The simplest oxocarbon is carbon monoxide CO. Carbon monoxide is a colorless, tasteless gas that is slightly lighter than air. It is toxic to humans and animals when encountered in higher concentrations, despite the fact that it is produced in the metabolism and is thought to have some biological functions.
Carbon Monoxide : Carbon monoxide is stabilized by three different resonance structures. The first resonance structure is the most important one. Carbon monoxide consists of one carbon and one oxygen atom connected by a triple bond. The distance between the carbon and oxygen atom is CO has three resonance structures, but the structure with the triple bond is the best approximation of the real distribution of electron density in the molecule.
CO is naturally produced by the human body as a signaling molecule. Abnormalities in its metabolism have been linked to a variety of diseases, including hypertension and heart failure. CO is present in small amounts in the atmosphere, mostly as a result of the burning of fossil fuels and fires. Through natural processes in the atmosphere, it is eventually oxidized to carbon dioxide CO 2. Carbon dioxide, or CO 2 , is a naturally occurring linear compound composed of two oxygen atoms covalently bonded to a carbon atom.
The compound is centrosymmetric and so has no net dipole. CO 2 is colorless; at high concentrations it has a sharp, acidic odor, but at lower concentrations it is odorless. At standard temperature and pressure, its density is 1.
It has no liquid state at pressures below kPa; at 1 atm, the gas deposits directly to a solid at temperatures below Solid CO 2 is known as dry ice. Carbon Dioxide : A central carbon atom is connected to two oxygen atoms via double bonds in a linear structure. Concentrations of the gas tend to fall during the northern spring and summer as plants consume the gas during the process of photosynthesis , and rise during autumn and winter as plants go dormant, decay, or die.
CO 2 is an end product of the metabolism of organisms via the cellular respiration process, in which energy is obtained from the breaking down of sugars, fats, and amino acids. Despite the fact that the human body produces approximately 2. Carbon dioxide is soluble in water; it reversibly converts to carbonic acid H 2 CO 3. The salt of carbonic acids are called carbonates and are characterized by the carbonate ion, CO 3 The carbonate ion is the simplest oxocarbon anion, consisting of one carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement.
The Lewis structure of the carbonate ion has two single bonds to negative oxygen atoms and one short double bond to a neutral oxygen. The symmetry can best be represented by three resonance structures.
The Carbonate Ion : The carbonate ion has three resonance structures. The true structure of the carbonate is an average of these three resonance structures.
In aqueous solutions, carbonate, bicarbonate HCO 3 — , carbon dioxide, and carbonic acid exist together in equilibrium. In strongly basic conditions, the carbonate ion predominates, while in weakly basic conditions, the bicarbonate ion predominates. In acidic conditions, aqueous CO 2 aq is the main form and is in equilibrium with carbonic acid — the equilibrium lies strongly towards carbon dioxide.
Metal carbonates generally decompose upon heating, liberating carbon dioxide and leaving behind an oxide of the metal. Most salts are insoluble in water, with solubility constants K sp less than 1 x 10 -8 , with the exception of lithium, sodium, potassium, and ammonium carbonates. Sodium carbonate is basic when dissolved in water meaning it results in a basic solution upon dissolution , and sodium bicarbonate is weakly basic.
Other fullerenes exist too, like C 70 , as well as ellipsoids and tubes. Use real life examples to help students get to grips with the properties of ceramics, polymers and composites. A new photocatalyst that can act on small alkane hydrocarbons is a rare example of directly using natural gases as reagents.
Classroom resources featuring activities from our Carbon Chemistry professional development course for teachers. Use this step-by-step to get your 14—16 students drawing electron configuration diagrams confidently. Site powered by Webvision Cloud. Skip to main content Skip to navigation.
Download this This infographic is designed to be displayed as a poster in the classroom though it could also be displayed on a projector or printed out as a handout. Diamond Structure Diamond has a tetrahedral structure. Structure Each carbon atom is covalently bonded to just three others, leaving one electron spare. Graphene Graphene was a theoretical concept before it was isolated and studied in by Andre Geim and Konstantin Novoselov at the University of Manchester, who were awarded the Nobel prize in physics in for their discovery.
When doped with alkali materials Na, K , the material becomes a superconductor with a transition temperature around 19 K for K3C Everything is basically explained in the presentation section. The main concepts are allotropic structures and how they change the resulting properties. A review of chemical bonding may be necessary. Skip to Main Content. Right item 1 Right item 2 Right item 3. Diamond is probably the most well known carbon allotrope. The carbon atoms are arranged in a lattice, which is a variation of the face-centered cubic crystal structure.
It has superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. Each carbon atom in a diamond is covalently bonded to four other carbons in a tetrahedron. These tetrahedrons together form a three-dimensional network of six-membered carbon rings in the chair conformation, allowing for zero bond-angle strain.
This stable network of covalent bonds and hexagonal rings is the reason that diamond is so incredibly strong as a substance. As a result, diamond exhibits the highest hardness and thermal conductivity of any bulk material. In addition, its rigid lattice prevents contamination by many elements. The surface of diamond is lipophillic and hydrophobic, which means it cannot get wet by water but can be in oil.
Diamonds do not generally react with any chemical reagents, including strong acids and bases. Uses of diamond include cutting, drilling, and grinding; jewelry; and in the semi-conductor industry. Graphite is another allotrope of carbon; unlike diamond, it is an electrical conductor and a semi-metal.
Graphite is the most stable form of carbon under standard conditions and is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. There are three types of natural graphite:.
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