carbon and its compounds

• The four main groups of organic compounds are hydrocarbons, alcohols, aldehydes/ketones, and carboxylic acids.
• Alcohols have the general formula R-OH (R is an alkyl group).
• Hydrocarbons contain only C and H atoms.
• Carbon is the most abundant element in living organisms.
• Carboxylic acids have the functional group -COOH.
• Alkanes are saturated hydrocarbons that have single bonds between their carbon atoms.
• Aldehydes and ketones both have the functional group -C=O but differ by their location on the molecule.
• Esters are formed when a carboxylic acid reacts with an alcohol.
• Carbon has four valence electrons that can be used to form covalent bonds with other atoms.
• The general formula for alcohols is ROH, where R represents an alkyl group.
• The general formula for aldehydes is RCHO, where R represents any organic radical.
• The general formula for alkanes is CnH2n+2, where n represents the number of carbons in the chain.
• The atomic number of carbon is 6, its electronic configuration is 2, 4, it requires 4 electrons to achieve the inert gas electronic configuration, but carbon cannot form an ionic bond.
• Carbon can gain four electrons forming C4- cation, but it would be difficult for the nucleus with six protons to hold on to ten electrons.
• Due to scum, a lot of soap gets wasted and cleansing action gets reduced to a larger extent.
• Scum: The insoluble precipitates formed by soap molecules when they react with calcium and magnesium ions present in hard water.
• Carbon can lose four electrons forming C4+ cations, but it requires a large amount of energy to remove four electrons.
• Carbon overcomes this problem by sharing of its valence electrons with other carbon atoms or with atoms of other elements.
• The bond formed by mutual sharing of electron pairs between two atoms in a molecule is known as Covalent Bond.
• Single Covalent Bond: When a single pair of electrons are shared between two atoms in a molecule, for example; F2, Cl2, H2 etc.
• Double Covalent Bond: When two pairs of electrons are shared between two atoms in a molecule, for example; O2, CO2 etc.
• Triple Covalent Bond: When three pairs of electrons are shared between two atoms in a molecule, for example; N2 etc.
• Electron Dot Structure: The electron dot structures provides a picture of bonding in molecules in terms of the shared pairs of electrons and octet rule.
• Formation of Hydrogen Molecule: Atomic number of Hydrogen = 1, Number of valence electrons = 1.
• Formation of CH4 Molecule: Atomic number of Carbon = 6 [2, 4], Number of valence electrons = 4.
• Carbon has Three Main Allotropes: Diamond, Graphite, Buckminster Fullerene.
• Diamond: In this, carbon, an atom is bonded to four other atoms of carbon forming three-dimensional structures, it is the hardest substance and an insulator, it is used for drilling rocks and cutting, it is also used for making jewellery.
• Graphite: In this, each carbon atom is bonded to three other carbon atoms, it is a good conductor of electricity and used as a lubricant.
• Buckminster Fullerene: It is an allotrope of the carbon-containing cluster of 60 carbon atoms joined together to form spherical molecules, it is dark solid at room temperature.
• Functional group, replacing the hydrogen is also called as heteroatom because it is different from carbon, and can be nitrogen, sulphur, or halogen, etc.
• Trivial or common names: These names were given after the source from which the organic compounds were first isolated, e.g., If a compound has one carbon atom, then its common name will have root word form and so on (see table).
• Presence of a functional group is indicated by prefix or suffix as given in table 2, and table 3.
• Replacement of hydrogen atom by a functional group is always in such a manner that valency of carbon remains satisfied.
• Symbol ‘R’ in a formula represents an Alkyl Group which is formed by the removal of one hydrogen atom from an alkane.
• Alkenes (with —C = C —) and Alkynes (with —C = C—) are unsaturated, whereas Alkanes (with — C — C—) are saturated compounds.
• Combustion Reaction: A chemical reaction in which a substance burns in the presence of air or oxygen is called combustion reaction.
• Versatile nature of Carbon, Hydrocarbons, Isomerism, Homologous series, Functional groups, Nomenclature of functional groups.
• A single line shown along with a functional group is called as its free valency by which it gets attached to a compound by replacing one hydrogen atom or atoms, e.g., -Cl.
• Isomerism: The phenomenon by means of which the carbon compounds with same molecular formula show different structures, and properties, e.g., A chain of 4 carbon atoms can be written in two ways :
• Combustion is always an EXOTHERMIC reaction.