Fixed-time period models are used when demand is variable

1Functional Groups and Chemical FamiliesAlthough there are a wide variety of organic compounds, most of them are composed of the elementsfrom the upper right hand portion of the periodic chart: C, H, N, O, S, Halogen. These compoundscan be categorized by certain structural and reactive features, dictated by the way carbon bonds toitself or another element, e.g. carbon double bonded to oxygen. Such a grouping of compoundsprovides us with the concept of chemical families. These special bonding arrangements have differentreactivities or functions and associated with each family is particular functional group.Rigorously speaking the functional group is not the whole molecule but only that collection of atomsthat provides a specific chemical function. For example, the chemical family of alcohols ischaracterized by the function of the hydroxyl (OH) group, and aldehydes, ketones are characterizedby carbonyl groups (C=O). There are various combinations of hydroxyl groups in molecules alongwith carbonyl groups and these combinations can lead to hydroxyketones and aldehydes (the basis forsugars) as well as to carboxylic acids. Indeed, esters, and amides also have carbonyl groups (C=O)but differ in their combination with an additional structural feature. To understand the reactivity ofchemical families one must consider the interplay between the various structural features in thatmolecule, and identifying the fundamental functional groups is a good place to start.Within a given family family members are arranged by the length of the longest carbon chain.Typically an organic compound will have a base name composed of a suffix to identify the family anda prefix to identify the length of the longest carbon chain. The first 10 prefixes aremeth-1hex-6eth-2hept-7prop-3oct-8but-4non-9pent-5dec-10The following provides a list of the more common chemical families exemplified as their pent-member.Hydrocarbons (all C,H)Alkanes
2Molecular formula CnH2n+2C5H12pentaneAlkenesMolecular formula CnH2nC5H10penteneAlkynesMolecular formula CnH2n-2C5H8pentyneCyclo(-alkanes, -alkenes, -alkynes)C10H16cyclodecynecyclopentenecyclopentaneC5H8C5H10ArenesC6H6benzeneHeteroatom Substituted Hydrocarbons