1 (574)

Prévia do material em texto

Glossary 509 Equilibrium The state of a reaction at which the concentrations of reactants and products no longer change. Ester In organic chemistry, a molecule whose functional group is oxygen singly bonded to a carbonyl group. Ester hydrolysis The reverse of esterification, leading to a carboxylic acid and an alcohol in the presence of excess water. Esterification The production of esters and water from alcohols and carboxylic acids in the presence of a mineral acid. Ether An organic molecule whose functional group is the alkoxy group. -OR. Exact mass The precise mass of the peaks of mass spectra. Excitation Discrete changes in the state of a molecule when it absorbs radiation. Exo adduct A bicyclic product with substituents placed cis with respect to the shorter bridge-in contrast to an endo adduct. Exothermic reaction A reaction releasing heat. giving a negative enthalpy change. Extended system A molecule with more than two conjugated double bonds. such as benzene. Fat An ester of long-chain carboxylic acids that is solid at room temperature-in contrast to liquid oils. Fatty acid The carboxylic acid parts of fats and oils. Fehling's test A chemical test for aldehydes by oxidation to a carboxylic acid and formation of cuprous oxide, a red precipitate. Fingerprint region The infrared spectrum between 600 and 1500 cm⁻¹. Fischer projection Representation of a configuration with horizontal lines for bonds pointed toward the viewer, vertical lines for bonds pointed away. Fischer-Tropsch reaction Catalytic synthesis of hydrocarbons from synthesis gas. Formaldehyde H₂C=0. the parent aldehyde-the aldehyde corresponding to formic acid. Formalin An aqueous solution of formaldehyde. a common disinfectant. Formic acid HCOOH. the parent carboxylic acid. Formyl group The group HCO-. Fragmentation pattern A mass spectrum showing the abundance of the characteristic fragments of a mol- ecular ion. Friedel-Crafts reactions Alkylation and alkanoylation (acylation) of benzene-electrophilic aromatic substitutions. Frontside displacement A (hypothetical) mechanism in which a nucleophile approaches from the same side as the leaving group. Fructose A ketohexose found in many fruits and honey. Fullerene A closed carbon shell. such as "buckyball." C₆₀. Functional group A group of atoms. also called a function. that controls an organic molecule's reactivity. Functionalization The introduction of a functional group. such as doubly or triply bonded carbon or other elements. into a molecule. Furan an aromatic heterocyclopentadiene. Furanose A five-membered cyclic monosaccharide. Fused ring A structure in which two rings share two adjacent carbon atoms. Gabriel synthesis Synthesis of a primary amine using 1.2-benzenedicarboxylic imide (phthalimide). Gauche conformation A staggered arrangement such that groups on adjacent carbon atoms are in contrast to anti. Geminal coupling Coupling between nonequivalent hydrogens on the same carbon atom. such as termi- nal hydrogens at a double bond. Geminal diol a carbonyl hydrate. change The mathematical function of temperature that governs a Gibbs standard free energy reaction equilibrium.