IOCHEM Lec

• Organic chemistry is a branch of chemistry that deals with the study of carbon and its compounds.
• Hydrocarbons usually contain hydrogen atoms and perhaps other atoms, such as oxygen, nitrogen, sulfur, and halogens.
• When two groups are on the benzene ring, three isomers are possible.
• The prefixes ortho-, meta-, and para- are used to indicate the position of two groups on the benzene ring.
• A numbering system is used to show the positions of two or more groups on the benzene ring.
• Aromatic hydrocarbons contain benzene rings, which are six-membered rings of carbon atoms with alternating single and double carbon-carbon bonds or similar structural features.
• Aliphatic hydrocarbons contain no benzene rings, are usually straight chain and sometimes closed chain.
• Saturated hydrocarbons have carbon to carbon single bonds, are usually soluble in water, and include methane (CH4) and ethane (C2H6).
• Unsaturated hydrocarbons contain double(=) or triple(≡) carbon to carbon bonds, are usually insoluble in water, and include heptene (C7H12) and heptene (C7H14).
• Alkane, also called as paraffins, is a hydrocarbon in which all carbon atoms are bonded to the maximum number of hydrogen atoms.
• Cycloalkanes are saturated hydrocarbons in which the carbon atoms form a ring.
• Alkene contains a carbon-carbon double bond, also called olefins.
• Alkynes are unsaturated hydrocarbons containing a carbon-carbon triple bond.
• Benzene is a six-membered ring of carbon atoms with alternating single and double carbon-carbon bonds.
• The simplest alkene is ethene or ethylene, which is a natural ripening agent for fruits.
• Upon metabolism by the plant, ethylene is converted into ethophon.
• Ethylene and ethophon are cis-trans isomers, which are isomers that have the same connectivity of their atoms but a different arrangement of their atoms in space.
• Cis-trans isomerism, also known as geometric isomerism or configurational isomerism, indicates that the functional groups are on the same side of the carbon chain while trans conveys that functional groups are on opposing sides of the carbon chain.
• Naming an alkene follows IUPAC rules, where the longest chain containing the double bond is assigned a number and the number of the carbon atom where the double bond is located is indicated.
• For branching alkene, the branch chains are named as in alkanes.
• A molecule that contains both double and triple bonds is called an alkenyne.
• The chain can be numbered starting with the end closest to the functional group that appears first.
• Basic rules of naming cycloalkenes include numbering the carbon atoms in the ring so that the double bond is between carbon atom1 and carbon atom2, giving lower numbers to the group/branch encountered first, and numbering and listing groups in alphabetical order.
• Aromatic hydrocarbon, also known as arene, is removed from an alkane by removing a hydrogen atom, which is called an alkyl group (R-).
• Aromatic hydrocarbon is removed from an arene by removing a hydrogen atom, which is called an aryl group (Ar-).
• Benzene, a type of aromatic hydrocarbon, is removed from an alkane by removing a hydrogen atom, which is called a phenyl group.
• Kekule structure is a type of fused-ring aromatic hydrocarbon.
• Rules in naming Benzene include assigning the smallest possible numbers to indicate the location of the branched alkanes.
• Fossil oil is a mixture of liquid alkanes and other hydrocarbons.
• Alkanes are Nonpolar, have Boiling points, melting points, and densities generally increases with the size of the alkane: Decane > Heptane > Butane.
• Straight chain alkanes have a higher boiling point than branched alkanes due to the greater surface area in contact.
• Alkanes containing 1 to 4 carbons are gases at room temperature.
• Alkanes containing 5 to 17 carbons are colorless liquids.
• Alkanes containing 18 or more carbons are white, waxy solids.
• Pentane to octane are reasonably volatile liquids that are used as fuels in internal combustion engines and are also good solvents for nonpolar substances.
• Nonane to hexadecane are used as kerosene and jet fuel.
• Alkanes from hexadecane are liquids of high viscosity and are commonly used as lubricating oil.
• Petroleum jelly, a semi-solid mixture of hydrocarbons (mainly higher than 25 carbons), is used as a skin protectant in cosmetic skin care.
• Many solid alkanes find use as paraffin wax in candles.
• Alkenes are non-polar, and they are both immiscible in water and less dense than water.