and hexafluoropropylene. Abbreviated FEP resin. {flu˙r⭈əna¯d⭈əd eth⭈əle¯n pro¯⭈
pəle¯n rez⭈ən }
fluorination [CHEM] A chemical reaction in which fluorine is introduced into a chemical compound. {flu˙r⭈əna¯⭈shən }
fluorine [CHEM] A gaseous or liquid chemical element, symbol F, atomic number 9, atomic weight 18.998403; a member of the halide family, it is the most electronegative element and the most chemically energetic of the nonmetallic elements; highly toxic, corrosive, and flammable; used in rocket fuels and as a chemical intermediate.
{flu˙re¯n }
fluoroacetate [ORG CHEM] Acetate in which carbon-connected hydrogen atoms are replaced by fluorine atoms. {¦flu˙r⭈o¯as⭈əta¯t }
fluoroacetic acid [ORG CHEM] CH2FCOOH A poisonous, crystalline compound obtained from plants, such as those of the Dichapetalaceae family, South Africa, soluble in water and alcohol, and burns with a green flame; the sodium salt is used as a water-soluble rodent poison. Also known as gifblaar poison. {¦flu˙r⭈o¯⭈əse¯d⭈ik as⭈əd } fluoroalkane [ORG CHEM] Straight-chain, saturated hydrocarbon compound (or analog
thereof) in which some of the hydrogen atoms are replaced by fluorine atoms.
{¦flu˙r⭈o¯alka¯n }
para-fluoroaniline [ORG CHEM] FC6H4NH2A liquid that is an intermediate in the manu-facture of herbicides and plant growth regulators. {¦par⭈ə flu˙r⭈o¯an⭈əle¯n } fluorobenzene [ORG CHEM] C6H5F A colorless liquid with a boiling point of 84.9⬚C; used
as an insecticide intermediate. Also known as phenyl fluoride. {¦flu˙r⭈o¯¦benze¯n } fluoroborate [INORG CHEM] 1.Any of a group of compounds related to the borates in which one or more oxygens have been replaced by fluorine atoms. 2.The BF4⫺ion, which is derived from fluoroboric acid, HBF4. Also known as fluoborate. {flu˙r⭈
əbo˙ra¯t }
fluoroboric acid [INORG CHEM] HBF4 Colorless, clear, water-miscible acid; used for electrolytic brightening of aluminum and for forming stabilized diazo salts. {¦flu˙r⭈
əbo˙r⭈ik as⭈əd }
fluorocarbon [ORG CHEM] A hydrocarbon in which part or all hydrogen atoms have been replaced by fluorine atoms, including chlorinated and brominated fluorocar-bons. Also known as fluorohydrocarbon. {¦flu˙r⭈o¯ka¨r⭈bən }
fluorocarbon-11See trichlorofluoromethane. {¦flu˙r⭈o¯ka¨r⭈bən əlev⭈ən } fluorocarbon-21See dichlorofluoromethane. {¦flu˙r⭈o¯ka¨r⭈bən twen⭈te¯wən } fluorocarbon fiber [ORG CHEM] Fiber made from a fluorocarbon resin, such as
polytetra-fluoroethylene resin. {¦flu˙r⭈o¯ka¨r⭈bən fı¯⭈bər }
fluorocarbon resin [ORG CHEM] Polymeric material made up of carbon and fluorine with or without other halogens (such as chlorine) or hydrogen; the resin is extremely inert and more dense than corresponding fluorocarbons such as Teflon. {¦flu˙r⭈
o¯ka¨r⭈bən rez⭈ən }
fluorochemical [CHEM] Any chemical compound containing fluorine; usually refers to the fluorocarbons. {¦flu˙r⭈o¯kem⭈ə⭈kəl }
fluorochlorocarbonSee chlorofluorocarbon. {¦flu˙r⭈o¯¦klo˙r⭈o¯ka¨r⭈bən }
fluorodichloromethaneSee dichlorofluoromethane. {¦flu˙r⭈o¯⭈dı¯klo˙r⭈o¯metha¯n } fluorodifen [ORG CHEM] C13H7F3N2O4A yellow, crystalline compound with a melting
point of 93⬚C; used as a pre- and postemergence herbicide for food crops. { flu˙ra¨d⭈
ə⭈fen }
1-fluoro-2,4-dinitrobenzene [ORG CHEM] (NO2)2C6H3F Crystals that are soluble in ben-zene, propylene glycol, and ether; used as a reagent for labeling terminal amino acid groups and in the detection of phenols. Also known as Sanger’s reagent.
{¦wən ¦flu˙r⭈o¯ ¦tu¨ ¦fo˙r dı¯nı¯⭈tro¯benze¯n }
fluoroform [ORG CHEM] CHF3A colorless, nonflammable gas, boiling point 84⬚C at 1 atmosphere (101,325 pascals), freezing point 160⬚C at 1 atmosphere; used in refrigeration and as an intermediate in organic synthesis. Also known as propellant 23; refrigerant 23; trifluoromethane. {flu˙r⭈əfo˙rm }
fluorogenic substrate [CHEM] A nonfluorescent material that is acted upon by an enzyme to produce a fluorescent compound. {flu˙r⭈əjen⭈ik səbstra¯t }
formaldehyde
fluorohydrocarbonSee fluorocarbon. {¦flu˙r⭈o¯hı¯⭈drəka¨r⭈bən }
fluorometric analysis [ANALY CHEM] A method of chemical analysis in which a sample, exposed to radiation of one wavelength, absorbs this radiation and reemits radiation of the same or longer wavelength in about 10⫺9second; the intensity of reemited radiation is almost directly proportional to the concentration of the fluorescing material. Also known as fluorescence analysis; fluorometry. {¦flu˙r⭈ə¦me⭈trik ənal⭈
ə⭈səs }
fluorometrySee fluorometric analysis. { flu˙ra¨m⭈ə⭈tre¯ }
para-fluorophenylacetic acid [ORG CHEM] FC6H4CH2COOH Crystals with a melting point of 86⬚C; used as an intermediate in the manufacture of fluorinated anesthetics.
{¦par⭈ə ¦flu˙⭈rəfen⭈əl⭈əse¯d⭈ik as⭈əd }
fluorophosphoric acid [INORG CHEM] H2PO3F A colorless, viscous liquid that is miscible with water; used in metal cleaners and as a catalyst. {¦flu˙r⭈o¯fa¨sfo˙r⭈ik as⭈əd } fluorotheneSee chlorotrifluoroethylene polymer. {flu˙r⭈əthe¯n }
fluorotrichloromethaneSee trichlorofluoromethane. {¦flu˙r⭈o¯⭈trı¯¦klo˙r⭈o¯metha¯n } fluosilicate [INORG CHEM] A salt derived from fluosilicic acid, H2SiF6, and containing
the SiF6⫺2ion. {¦flu¨⭈əsil⭈əka¯t }
fluosilicic acid [INORG CHEM] H2SiF6A colorless acid, soluble in water, which attacks glass and stoneware; highly corrosive and toxic; used in water fluoridation and electroplating. Also known as hydrofluorosilicic acid; hydrofluosilicic acid. {¦flu¨⭈
ə⭈səlis⭈ik as⭈əd }
fluosulfonic acid [INORG CHEM] HSO3F Colorless, corrosive, fuming liquid; soluble in water with partial decomposition; used as organic synthesis catalyst and in elec-troplating. {¦flu¨⭈ə⭈səlfa¨n⭈ik as⭈əd }
flurenol [ORG CHEM] C18H18O3A solid, crystalline compound with a melting point of 70–71⬚C; used as an herbicide for vegetables, cereals, and ornamental flowers.
{flu˙r⭈əno˙l }
fluxional compound [ORG CHEM]1.Any of a group of molecules which undergo rapid intramolecular rearrangements in which the component atoms are interchanged among equivalent structures. 2.Molecules in which bonds are broken and reformed in the rearrangement process. {flək⭈shən⭈əl ka¨mpau˙nd }
FmSee fermium.
foam [CHEM] An emulsionlike two-phase system where the dispersed phase is gas or air. { fo¯m }
folic acid sodium saltSee sodium folate. {¦fo¯⭈lik ¦as⭈əd ¦so¯d⭈e¯⭈əm so˙lt }
folimat [ORG CHEM] C5H12NO4PS An oily liquid that decomposes at 135⬚C; soluble in water; used as an insecticide and miticide on fruit and vegetable crops and on ornamental flowers. Also known as omethioate. {fa¨⭈ləmat }
Folin solution [ANALY CHEM] An aqueous solution of 500 grams of ammonium sulfate, 5 grams of uranium acetate, and 6 grams of acetic acid in a volume of 1 liter; used to test for uric acid. {fo¯⭈lən səlu¨⭈shən }
folpet [ORG CHEM] C9H4Cl3NO2S A buff or white, crystalline compound with a melting point of 177–178⬚C; insoluble in water; used as a fungicide on fruits, vegetables, and ornamental flowers. {fa¨l⭈pet }
foot’s oil [CHEM] The oil sweated out of slack wax; it takes its name from the fact that it goes to the bottom, or foot, of the pan when sweated. {fu˙ts o˙il }
force constant [PHYS CHEM] An expression for the force acting to restrain the relative displacement of the nuclei in a molecule. {fo˙rs ka¨n⭈stənt }
forced-flow boiling [PHYS CHEM] Boiling of a liquid whose flow over a heater surface is imposed by external means. {¦forst ¦flo¯ bo˙il⭈iŋ }
force field methodSee molecular mechanics. {fo˙rs ¦fe¯ld meth⭈əd }
formal charge [PHYS CHEM] The apparent charge of an element in a compound; for example, magnesium has a formal charge of⫹2 in MgO and oxygen has a charge of⫺2. { ¦fo˙r⭈məl ¦cha¨rj }
formaldehyde [ORG CHEM] HCHO The simplest aldehyde; a gas at room temperature, and a poisonous, clear, colorless liquid solution with pungent odor; used to make
formaldehyde sodium bisulfite
synthetic resins by reaction with phenols, urea, and melamine, as a chemical interme-diate, as an embalming fluid, and as a disinfectant. Also known as formol; methanal;
methylene oxide. { fo˙rmal⭈dəhı¯d }
formaldehyde sodium bisulfite [ORG CHEM] CH3NaO4S A compound used as a fixing agent for fibers containing keratin, in metallurgy for flotation of lead-zinc ores, and in photography. { fo˙rmal⭈dəhı¯d ¦so¯d⭈e¯⭈əm bı¯səlfı¯t }
formality [CHEM] A concentration scale that gives the number of formula weights of solute per liter of solution; designated by F preceded by a number to show solute concentration. { fo˙rmal⭈əd⭈e¯ }
formamide [ORG CHEM]1.A compound containing the radical HCONH. 2.HCONH2
A clear, colorless hygroscopic liquid, boiling at 200–212⬚C; soluble in water and alcohol; used as a solvent, softener, and chemical intermediate. Also known as formylamine; methanamide. { fo˙rmam⭈əd }
formamidinesulfinic acid [ORG CHEM] H2NC(NH)SO2H A reagent for the reduction of ketones to secondary alcohols. { fo˙r¦mam⭈əde¯n⭈səlfin⭈ik as⭈əd }
formate [ORG CHEM] A compound containing the HCOO⫺functional group.
{fo˙rma¯t }
formic acid [ORG CHEM] HCOOH A colorless, pungent, toxic, corrosive liquid melting at 8.4⬚C; soluble in water, ether, and alcohol; used as a chemical intermediate and solvent, in dyeing and electroplating processes, and in fumigants. Also known as methanoic acid. {¦fo˙r⭈mik as⭈əd }
formic etherSee ethyl formate. {fo˙r⭈mik e¯⭈thər } formolSee formaldehyde. {fo˙rmo˙l }
formonitrileSee hydrocyanic acid. {¦fo˙r⭈mo¯¦nı¯⭈trəl }
formula [CHEM]1.A combination of chemical symbols that expresses a molecule’s composition. 2.A reaction formula showing the interrelationship between reactants and products. {fo˙r⭈myə⭈lə }
formulation [CHEM] The particular mixture of base chemicals and additives required for a product. {fo˙r⭈myəla¯⭈shən }
formula weight [CHEM]1.The gram-molecular weight of a substance. 2.In the case of a substance of uncertain molecular weight such as certain proteins, the molecular weight calculated from the composition, assuming that the element present in the smallest proportion is represented by only one atom. {fo˙r⭈myə⭈lə wa¯t } formyl [ORG CHEM] The formic acid radical, HCO⫺; it is characteristic of aldehydes.
{fo˙rmil }
formylamineSee formamide. {fo˙r⭈məlame¯n }
Fortrat parabola [SPECT] Graph of wave numbers of lines in a molecular spectral band versus the serial number of the successive lines. {fo˙rtra¨ pərab⭈ə⭈lə }
Foulger’s test [ANALY CHEM] A test for fructose in which urea, sulfuric acid, and stan-nous chloride are added to the solution to be tested, the solution is boiled, and in the presence of fructose a blue coloration forms. { fu¨lja¯z test }
four-degree calorie [CHEM] The heat needed to change the temperature of 1 gram of water from 3.5 to 4.5⬚C. { ¦fo˙r di¦gre¯ kal⭈ə⭈re¯ }
Fourier transform spectroscopy [SPECT] A spectroscopic technique in which all perti-nent wavelengths simultaneously irradiate the sample for a short period of time, and the absorption spectrum is found by mathematical manipulation of the Fourier transform so obtained. {¦fu˙r⭈e¯¦a¯ tranzfo˙rm spektra¨s⭈kə⭈pe¯ }
fpSee freezing point.
FrSee francium.
fraction [CHEM] One of the portions of a volatile liquid within certain boiling point ranges, such as petroleum naphtha fractions or gas-oil fractions. {frak⭈shən } fractional condensation [CHEM] Separation of components of vaporized liquid
mix-tures by condensing the vapors in stages (partial condensation); highest-boiling-point components condense in the first condenser stage, allowing the remainder of the vapor to pass on to subsequent condenser stages. {¦frak⭈shən⭈əl ka¨n⭈
densa¯⭈shən }