Chemistry Dictionary

In this site we focused on the the areas of science incluod analytical chemisty, general chemistry, inorganic chemistry, organic chemistry, physical chemistry, and spectroscopy.(Online Chemistry Dictionary )

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16.7.11

ammonia

  11:59 AM    Anonymous

ammonia [INORGCHEM]NH3 A colorless gaseous alkaline compound that is very soluble
in water, has a characteristic pungent odor, is lighter than air, and is formed as a
result of the decomposition of most nitrogenous organic material; used as a fertilizer
and as a chemical intermediate.

   /

ammonation

  11:59 AM    Anonymous

ammonation [INORG CHEM] A reaction in which ammonia is added to other molecules
or ions by covalent bond formation utilizing the unshared pair of electrons on the
nitrogen atom, or through ion-dipole electrostatic interactions.

   /

ammine

  11:58 AM    Anonymous

ammine [INORG CHEM] One of a group of complex compounds formed by coordination
of ammonia molecules with metal ions.

   /

aminotriazole

  11:58 AM    Anonymous

aminotriazole [ORG CHEM]C2H4N4 Crystals with a melting point of 159 C; soluble in
water, methanol, chloroform, and ethanol; used as an herbicide, cotton plant defoli-
ant, and growth regulator for annual grasses and broadleaf and aquatic weeds.
Abbreviated ATA.

   /

2-aminothiazole

  11:58 AM    Anonymous

2-aminothiazole [ORG CHEM]C3H4N2S Pale-yellow crystals that melt at 92 C; soluble
in cold water, slightly soluble in ethyl alcohol; used as an intermediate in the
synthesis of sulfathiazole.

   /

amino resin

  11:57 AM    Anonymous

amino resin [ORG CHEM] A type of resin prepared by condensation polymerization,
with an aldehyde, of a compound containing an amino group.

   /

beta aminopyridine

  11:57 AM    Anonymous

beta aminopyridine [ORG CHEM]C5H6N2 Crystals with a melting point of 64 C; soluble in
water, alcohol, and benzene; used in drug and dye manufacture. Also known as
3-aminopyridine.

   /

4aminopyridine

  11:56 AM    Anonymous

4-aminopyridine [ORG CHEM]C5H6N2 White crystals with a melting point of 158.9 C;
soluble in water; used as a repellent for birds. Abbreviated 4-AP.

   /

para-aminophenol

  11:54 AM    Anonymous

para-aminophenol [ORG CHEM] p-HOC6H4NO2 A phenol in which an amino ( NH2)
group is located on the benzene ring of carbon atoms para (p) to the hydroxyl ( OH)
group; used as a photographic developer and as an intermediate in dye manufacture

   /

aminophenol

  11:53 AM    Anonymous

aminophenol [ORG CHEM] A type of compound containing the NH2 and OH groups
joined to the benzene ring; examples are para-aminophenol and ortho-hydroxylaniline.

   /

amino nitrogen

  11:52 AM    Anonymous

amino nitrogen [CHEM] Nitrogen combined with hydrogen in the amino group. Also
known as ammonia nitrogen.

   /

3-amino-2-naphthoic acid

  11:51 AM    Anonymous

3-amino-2-naphthoic acid [ORG CHEM]H2NC10H6COOH Yellow crystals in the shape
of scales with a melting point of 214 C; soluble in alcohol and ether; used in the
determination of copper, nickel, and cobalt.

   /

2-amino-2-methyl-1,3-propanediol

  11:50 AM    Anonymous

2-amino-2-methyl-1,3-propanediol [ORG CHEM] HOCH2C(CH3)(NH2)CH2OH Crystals
with amelting point of 109–111 C; soluble in water and alcohol; used in the synthesis
of surface-active agents, pharmaceuticals, and vulcanizers, and as an emulsifying
agent for cosmetics, leather dressings, polishes, and cleaning compounds.

   /

amino group

  11:04 AM    Anonymous

amino group [ORG CHEM] A functional group ( NH2) formed by the loss of a hydrogen
atom from ammonia. 

   /

3-amino-2,5-dichlorobenzoic acid

  11:03 AM    Anonymous

3-amino-2,5-dichlorobenzoic acid [ORG CHEM]C7H5O2NCl2 A white solid with a melt-
ing point of 200–201 C; solubility in water is 700 parts per million at 20 C; used as
a preemergence herbicide for soybeans, corn, and sweet potatoes.

   /

aminodiborane

  11:03 AM    Anonymous

aminodiborane [INORG CHEM] Any compound derived from diborane (B2H6) in which
one H of the bridge has been replaced by NH2.

   /

aminocarb

  11:02 AM    Anonymous

aminocarb [ORG CHEM]C11H16N2O2 A tan, crystalline compound with a melting point
of 93–94 C; slightly soluble in water; used as an insecticide for control of forest
insects and pests of cotton, tomatoes, tobacco, and fruit crops.

   /

gama - aminobutyric acid

  11:01 AM    Anonymous

gama - aminobutyric acid [ORG CHEM]H2NCH2CH2CH2COOH Crystals which are either leaf-
lets or needles, with a melting point of 202 C; thought to be a central nervous system
postsynaptic inhibitory transmitter. Abbreviated GABA.

   /

E - aminocaproic acid

  10:59 AM    Anonymous

E - aminocaproic acid [ORG CHEM]C6H13NO2 Crystals with amelting point of 204–206 C;
freely soluble in water; used as an antifibrinolytic agent and a spacer for affinity
chromatography. 

   /

2-amino-1-butanol

  9:39 AM    Anonymous

2-amino-1-butanol [ORG CHEM]CH3CH2CH(NH2)CH2OH A liquid miscible with water,
soluble in alcohols; used in the synthesis of surface-active agents, vulcanizing acceler-
ators, and pharmaceuticals, and as an emulsifying agent for such products as cosmetic
creams and lotions.

   /

1-aminoanthraquinone

  9:39 AM    Anonymous

1-aminoanthraquinone [ORG CHEM]C14H9NO2 Ruby-red crystals with a melting point
of 250 C; freely soluble in alcohol, benzene, chloroform, ether, glacial acetic acid,
and hydrochloric acid; used in the manufacture of dyes and pharmaceuticals.

   /

amino , amin

  9:38 AM    Anonymous

amino-, amin- [CHEM] Having the property of a compound in which the group NH2 is
attached to a radical other than an acid radical. 

   /

15.7.11

amine

  3:40 PM    Anonymous

amine [ORG CHEM] One of a class of organic compounds which can be considered to
be derived from ammonia by replacement of one or more hydrogens by functional
groups.

   /

amination

  3:40 PM    Anonymous

amination [ORG CHEM] 1. The preparation of amines. 2. A process in which the amino
group ( NH2) is introduced into organic molecules.

   /

amidol

  3:39 PM    Anonymous

amidol [ORG CHEM]C6H3(NH2)2OH HCl A grayish-white crystalline salt; soluble in
water, slightly soluble in alcohol; used as a developer in photography and as an
analytical reagent.

   /

amido

  3:38 PM    Anonymous

amido [ORG CHEM] Indicating the NH2 radical when it is present in a molecule with
the CO radical.

   /

amide hydrolysis

  3:38 PM    Anonymous

amide hydrolysis [ORG CHEM] The cleavage of an amide into its constitutive acid and
amine fragments by a net addition of water.

   /

amide

  3:37 PM    Anonymous

amide [ORG CHEM] One of a class of organic compounds containing the CONH2 radical.

   /

amidation

  3:36 PM    Anonymous

amidation [ORG CHEM] The process of forming an amide; for example, in the laboratory
benzyl reacts with methyl amine to form N-methylbenzamide.

   /

amicron

  3:36 PM    Anonymous

amicron [PHYS CHEM] A particle having a size of 10 7
centimeter or less, which is a
size in a system of classification of particle sizes in colloid chemistry.

   /

Ames test

  3:35 PM    Anonymous

Ames test [ANALY CHEM] A bioassay that uses a set of histidine auxotrophic mutants of
Salmonella typhimurium for detectingmutagenic and possibly carcinogenic compounds.

   /

americium

  3:35 PM    Anonymous

americium [CHEM] A chemical element, symbol Am, atomic number 95; the mass
number of the isotope with the longest half-life is 243.

   /

ambident

  3:34 PM    Anonymous

ambident [ORG CHEM] A chemical species or molecule that possesses two alternative
reactive sites, either of which can bond in a reaction; examples include cyanate ions,
thiosulfate ions, oxime anions, and enolate ions. Also known as ambidentate.

   /

Am

  3:33 PM    Anonymous

Am See americium

   /

aluminum sulfate

  10:31 AM    Anonymous

aluminum sulfate [INORG CHEM]Al2(SO4)3 18H2O A colorless salt in the form of mono-
clinic crystals that decompose in heat and are soluble in water; used in papermaking,
water purification, and tanning, and as a mordant in dyeing. Also known as alum.

   /

aluminum stearate

  10:31 AM    Anonymous

aluminum stearate [ORG CHEM] Al(C17H35COO)3 An aluminum soap in the form of a
white powder that is insoluble in water and soluble in oils; used for waterproofing
fabrics and concrete and as a drier in paints and varnishes.

   /

aluminum sodium sulfate

  10:30 AM    Anonymous

aluminum sodium sulfate [INORG CHEM] AlNa(SO4)2 12H2O Colorless crystals with an
astringent taste and a melting point of 61 C; soluble in water; used as a mordant
and for waterproofing textiles, as a food additive, and for matches, tanning, ceramics,
engraving, and water purification. Abbreviated SAS. Also known as porous alum;
soda alum; sodium aluminum sulfate.

   /

aluminum soap

  10:30 AM    Anonymous

aluminum soap [ORG CHEM] Any of various salts of higher carboxylic acids and alumi-
num that are insoluble in water and soluble in oils; used in lubricating greases,
paints, varnishes, and waterproofing substances.

   /

aluminum silicate

  10:28 AM    Anonymous

aluminum silicate [INORG CHEM]Al2(SiO3)3 A white solid that is insoluble in water;
used as a refractory in glassmaking.

   /

aluminum palmitate

  10:27 AM    Anonymous

aluminum palmitate [ORG CHEM] Al(C16H31O2) H2O An aluminum soap used in water-
proofing fabrics, paper, and leather and as a drier in paints.

   /

aluminum oxide

  10:26 AM    Anonymous

aluminum oxide [INORG CHEM]Al2O3 A compound in the form of a white powder or
colorless hexagonal crystals; melts at 2020 C; insoluble in water; used in aluminum
production, paper, spark plugs, absorbing gases, light bulbs, artificial gems, and
manufacture of abrasives, refractories, ceramics, and electrical insulators.

   /

aluminum orthophosphate

  10:26 AM    Anonymous

aluminum orthophosphate [INORG CHEM] AlPO4 White crystals, melting above 1500 C;
insoluble in water, soluble in acids and bases; useful in ceramics, paints, pulp, and
paper. Also known as aluminum phosphate.

   /

aluminum oleate

  10:25 AM    Anonymous

aluminum oleate [ORG CHEM] A soaplike compound of aluminum and oleic acid, used
in lubricating oils and greases to improve their viscosity.

   /

aluminum nitrate

  10:25 AM    Anonymous

aluminum nitrate [INORG CHEM] Al(NO3)3 9H2O White, deliquescent crystals with a melting point of 73 C; soluble in alcohol and acetone; used as a mordant for textiles,
in leather tanning, and as a catalyst in petroleum refining.

   /

aluminum monostearate

  10:24 AM    Anonymous

aluminum monostearate [ORG CHEM] Al(OH)2[OOC(CH2)16CH3] A white to yellowish-
white powder with a melting point of 155 C; used in the manufacture of medicine,
paint, and ink, in waterproofing, and as a plastics stabilizer.

   /

aluminum fluosilicate

  10:22 AM    Anonymous

aluminum fluosilicate [INORG CHEM]Al2(SiF6)3 A white powder that is soluble in hot
water; used for artificial gems, enamels, and glass. Also known as aluminum sili-
cofluoride.

   /

aluminum chloride

  10:21 AM    Anonymous

aluminum chloride [INORG CHEM] AlCl3 or Al2Cl6 A deliquescent compound in the form
of white to colorless hexagonal crystals; fumes in air and reacts explosively with
water; used as a catalyst.

   /

aluminum borohydride

  10:21 AM    Anonymous

aluminum borohydride [ORG CHEM] Al(BH4)3 A volatile liquid with a boiling point of
44.5 C; used in organic synthesis and as a jet fuel additive.

   /

aluminum acetate

  10:20 AM    Anonymous

aluminum acetate [ORG CHEM] Al(CH3COO)3 A white, amorphous powder that is solu-
ble in water; used in aqueous solution as an antiseptic.

   /

aluminum

  10:20 AM    Anonymous

aluminum [CHEM] A chemical element, symbol Al, atomic number 13, and atomic
weight 26.9815. Also spelled aluminium.

   /

aluminosilicate

  10:19 AM    Anonymous

aluminosilicate [INORG CHEM] 3Al2O3 2SiO2 A colorless, crystalline combination of sili-
cate and aluminate in the form of rhombic crystals.

   /

aluminon

  10:19 AM    Anonymous

aluminon [ORG CHEM]C22H23N3O9 A yellowish-brown, glassy powder that is freely solu-
ble in water; used for the detection and colorimetric estimation of aluminum in
foods, water, and tissues, and as a pharyngeal aerosol spray.

   /

14.7.11

alumina trihydrate

  3:35 PM    Anonymous

alumina trihydrate [INORG CHEM]Al2O3 3H2O, or Al(OH)3 A white powder; insoluble in
water, soluble in hydrochloric or sulfuric acid or sodium hydroxide; used in the
manufacture of ceramic glasses and in paper coating. Also known as aluminum
hydrate; aluminum hydroxide; hydrated alumina; hydrated aluminum oxide.

   /

aluminate

  3:28 PM    Anonymous

aluminate [INORG CHEM] A negative ion usually assigned the formula AlO2
and derived
from aluminum hydroxide.

   /

alumina

  10:09 AM    Anonymous

alumina [INORG CHEM]Al2O3 The native formof aluminumoxide occurring as corundum
or in hydrated forms, as a powder or crystalline substance.

   /

alum

  10:09 AM    Anonymous

alum [INORG CHEM] 1. Any of a group of double sulfates of trivalent metals such as
aluminum, chromium, or iron and a univalent metal such as potassium or sodium.
2. See aluminumsulfate; ammoniumaluminumsulfate; potassiumaluminumsulfate.

   /

alternation of multiplicities law

  10:08 AM    Anonymous

alternation of multiplicities law [CHEM] The law that the periodic table arranges the
elements in such a sequence that their number of orbital electrons, and hence their
multiplicities, alternates between even and odd numbers.

   /

alternating copolymer

  10:08 AM    Anonymous

alternating copolymer [ORG CHEM] A polymer formed of two different monomer mole-
cules that alternate in sequence in the polymer chain.

   /

alternant hydrocarbon

  10:07 AM    Anonymous

alternant hydrocarbon [ORG CHEM] A member of a class of conjugated molecules
whose carbon atoms can be divided into two sets so that members of one set are
formally bonded only to members of the other set.

   /

alpha position

  10:07 AM    Anonymous

alpha position [ORG CHEM] In chemical nomenclature, the position of a substituting
group of atoms in the main group of a molecule; for example, in a straight-chain compound such as -hydroxypropionic acid (CH3CHOHCOOH), the hydroxyl radical
is in the alpha position.

   /

alpha olefin

  10:06 AM    Anonymous

alpha olefin [ORG CHEM] An olefin where the unsaturation (double bond) is at the
alpha position, that is, between the two end carbons of the carbon chain.

   /

alpha cellulose

  10:05 AM    Anonymous

alpha cellulose [ORG CHEM] A highly refined, insoluble cellulose from which sugars,
pectin, and other soluble materials have been removed. Also known as chemical
cellulose

   /

allyxycarb

  10:05 AM    Anonymous

allyxycarb [ORG CHEM]C16H22N2O2 A yellow, crystalline compound used as an insecti-
cide for fruit orchards, vegetable crops, rice, and citrus

   /

allylurea

  10:04 AM    Anonymous

allylurea [ORG CHEM]C4H8N2O Crystals with a melting point of 85 C; freely soluble in
water and alcohol; used to manufacture allylthiourea and other corrosion inhibitors.

   /

allyltrichlorosilane

  10:02 AM    Anonymous

allyltrichlorosilane [ORG CHEM]CH2CHCH2SiCl3 A pungent, colorless liquid with a boil-
ing point of 117.5 C; used as an intermediate for silicones.

   /

allylthiourea

  10:01 AM    Anonymous

allylthiourea [ORG CHEM]C3H5NHCSNH2 A white, crystalline solid that melts at 78 C;
soluble in water; used as a corrosion inhibitor.

   /

allyl sulfide

  10:01 AM    Anonymous

allyl sulfide [ORG CHEM] (CH2CHCH2)2S A colorless liquid with a garliclike odor and a
boiling point of 139 C; used in synthetic oil of garlic.

   /

allyl resin

  10:00 AM    Anonymous

allyl resin [ORG CHEM] Any of a class of thermosetting synthetic resins derived from
esters of allyl alcohol or allyl chloride; used in making cast and laminated products.
Also known as allyl plastic.

   /

allyl mercaptan

  9:59 AM    Anonymous

allyl mercaptan [ORG CHEM]CH2CHCH2SH A colorless liquid with a boiling point of
67–68 C; soluble in ether and alcohol; used as intermediate in pharmaceutical
manufacture.

   /

allyl isothiocyanate

  9:59 AM    Anonymous

allyl isothiocyanate [ORG CHEM]CH2CH:CH2NCS A pungent, colorless to pale-yellow
liquid; soluble in alcohol, slightly soluble in water; irritating odor; boiling point
152 C; used as a fumigant and as a poison gas. Also known as mustard oil.

   /

allylic substitution

  9:58 AM    Anonymous

allylic substitution [ORG CHEM] A reaction occurring at position 1 of an allylic system
(with the double bond between positions 2 and 3) in which the incoming group is
attached to the same atom (position 1) as the leaving group, or the incoming group
is attached at position 3, with the double bond moving from positions 2 and 3 to
positions 1 and 2.

   /

allylic hydrogen

  9:58 AM    Anonymous

allylic hydrogen [ORG CHEM] In an organic molecule, a hydrogen attached to a carbon
atom that is adjacent to a double bond.

   /

allylene

  9:57 AM    Anonymous

allylene [ORG CHEM]CH3C:CH An acetylenic, three-carbon hydrocarbon; a colorless
gas boiling at 24 C; soluble in ether.

   /

allyl cyanide

  9:57 AM    Anonymous

allyl cyanide [ORG CHEM]C4H5N A liquid with an onionlike odor and a boiling point
of 119 C; slightly soluble in water; used as a cross-linking agent in polymerization.

   /

allyl chloride

  9:56 AM    Anonymous

allyl chloride [ORG CHEM]CH2CHCH2Cl A volatile, pungent, toxic, flammable, colorless
liquid, boiling at 46 C; insoluble in water; made by chlorination of propylene at high
temperatures.

   /

allyl cation

  9:56 AM    Anonymous

allyl cation [ORG CHEM] A carbonium cation with a structure usually represented as
CH2 CH CH2
+; attachment site is the saturated carbon atom.

   /

allyl bromide

  9:55 AM    Anonymous

allyl bromide [ORG CHEM]C3H5Br A colorless to light yellow, irritating toxic liquid with
a boiling point of 71.3 C; soluble in organic solvents; used in organic synthesis and
for the manufacture of synthetic perfumes.

   /

12.7.11

allylamine

  7:59 PM    Anonymous

allylamine [ORG CHEM]CH2CHCH2NH2 A yellow oil that is miscible with water; boils
at 58 C; prepared from mustard oil.

   /

allyl alcohol

  7:54 PM    Anonymous

allyl alcohol [ORG CHEM]CH2CHCH2OH Colorless, pungent liquid, boiling at 96 C;
soluble in water; made from allyl chloride by hydrolysis.

   /

allyl alcohol

  7:52 PM    Anonymous

allyl alcohol [ORG CHEM]CH2CHCH2OH Colorless, pungent liquid, boiling at 96 C;
soluble in water; made from allyl chloride by hydrolysis.

   /

allylacetone

  7:51 PM    Anonymous

allylacetone [ORG CHEM]CH2CHCH2CH2COCH3 A colorless liquid, soluble in water and organic solvents; used in pharmaceutical synthesis, perfumes, fungicides, and
insecticides.

   /

allyl

  7:48 PM    Anonymous

allyl- [ORG CHEM] A prefix used in names of compounds whose structure contains an
allyl cation.

   /

allulose

  7:46 PM    Anonymous

allulose [ORG CHEM]CH2OHCO(CHOH)3CH2OH A constituent of cane sugar molasses;
it is nonfermentable.

   /

10.7.11

allotropy

  11:57 AM    Anonymous

allotropy [CHEM] The assumption by an element of two or more different forms or
structures which are most frequently stable in different temperature ranges, such
as different crystalline forms of carbon as charcoal, graphite, or diamond. Also
known as allotriomorphism; allotropism.

  

9.7.11

allotrope

  6:15 PM    Anonymous

allotrope [CHEM] A form of an element showing allotropy.

   /

allo

  6:14 PM    Anonymous

allo- [CHEM] Prefix applied to the stabler form of two isomers.

   /

allidochlor

  6:14 PM    Anonymous

allidochlor [ORG CHEM]C8H12NOCl An amber liquid having slight solubility in water;
used as a preemergence herbicide for vegetable crops, soybeans, sorghum, and
ornamentals.

   /

allethrin

  6:13 PM    Anonymous

allethrin [ORG CHEM] An insecticide, a synthetic pyrethroid, more effective than pyre-
thrin.

   /

allene

  6:13 PM    Anonymous

allene [ORG CHEM]C3H4 An unsaturated aliphatic hydrocarbon with two double bonds.
Also known as propadiene.

   /

allelochemistry

  6:13 PM    Anonymous

allelochemistry [CHEM] The science of compounds synthesized by one organism that
stimulate or inhibit other organisms.

   /

alkyne

  6:12 PM    Anonymous

alkyne [ORG CHEM] One of a group of organic compounds containing a carbon-to-
carbon triple bond.

   /

alkyl halide

  6:11 PM    Anonymous

alkyl halide [ORG CHEM] A compound consisting of an alkyl group and a halogen; an
example is ethylbromide.

   /

alkylene

  6:11 PM    Anonymous

alkylene [ORG CHEM] An organic radical formed froman unsaturated aliphatic hydrocar-
bon; for example, the ethylene radical C2H3 .

   /

alkylation

  6:10 PM    Anonymous

alkylation [ORG CHEM] A chemical process in which an alkyl radical is introduced into
an organic compound by substitution or addition.

   /

alkylate

  6:09 PM    Anonymous

alkylate [ORG CHEM] A product of the alkylation process in petroleum refining.

   /

alkylamine

  6:08 PM    Anonymous

alkylamine [ORG CHEM] A compound consisting of an alkyl group attached to the
nitrogen of an amine; an example is ethylamine, C2H5NH2.

   /

alkyl

  6:08 PM    Anonymous

alkyl [ORG CHEM] An organic group that results from removal of a hydrogen atom from
an acyclic, saturated hydrocarbon; may be represented in a chemical formula by
R .

   /

alkyd resin

  6:07 PM    Anonymous

alkyd resin [ORG CHEM] A class of adhesive resins made from unsaturated acids and
glycerol.

   /

alkoxy

  6:07 PM    Anonymous

alkoxy [ORG CHEM] An alkyl radical attached to a molecule by oxygen, such as the
ethoxy radical.

   /

alkene

  6:06 PM    Anonymous

alkene [ORG CHEM] One of a class of unsaturated aliphatic hydrocarbons containing
one or more carbon-to-carbon double bonds.

   /

alkanolamine

  6:06 PM    Anonymous

alkanolamine [ORG CHEM] One of a group of viscous, water-soluble amino alcohols of
the aliphatic series.

   /

alkannin

  6:05 PM    Anonymous

alkannin [ORG CHEM]C16H16O5 A red powder, the coloring ingredient of alkanet; soluble
in alcohol, benzene, ether, and oils; used as a coloring agent for fats and oils, wines,
and wax.

   /

alkane

  6:05 PM    Anonymous

alkane [ORG CHEM] A member of a series of saturated aliphatic hydrocarbons having the empirical formula CnH2n+2. Also known as paraffin; paraffinic hydrocarbon.

   /

alkamine

  6:03 PM    Anonymous

alkamine [ORG CHEM] A compound that has both the alcohol and amino groups. Also
known as amino alcohol.

   /

alkaloid

  6:02 PM    Anonymous

alkaloid [ORG CHEM] One of a group of nitrogenous bases of plant origin, such as
nicotine, cocaine, and morphine.

   /

alkalinity

  6:02 PM    Anonymous

alkalinity [CHEM] The property of having excess hydroxide ions in solution.

   /

alkaline earth metals

  6:01 PM    Anonymous

alkaline-earth metals [CHEM] The heaviest members of group 2 in the periodic table;
usually calcium, strontium, magnesium, and barium.

   /

alkaline earth

  6:00 PM    Anonymous

alkaline earth [INORG CHEM] An oxide of an element of group 2 in the periodic table,
such as barium, calcium, and strontium. Also known as alkaline-earth oxide.

   /

alkaline

  6:00 PM    Anonymous

alkaline [CHEM] 1. Having properties of an alkali. 2. Having a pH greater than 7.

   /

alkalimetry

  5:59 PM    Anonymous

alkalimetry [ANALY CHEM] Quantitative measurement of the concentration of bases or
the quantity of one free base in a solution; techniques include titration and other
analytical methods.

   /

alkalimeter

  5:59 PM    Anonymous

alkalimeter [ANALY CHEM] 1. An apparatus for measuring the quantity of alkali in a
solid or liquid. 2. An apparatus for measuring the quantity of carbon dioxide formed
in a reaction.

   /

alkali metal

  5:59 PM    Anonymous

alkali metal [CHEM] Any of the elements of group I in the periodic table: lithium,
sodium, potassium, rubidium, cesium, and francium.

   /

alkalide

  5:58 PM    Anonymous

alkalide [INORG CHEM] A member of a class of crystalline salts with an alkali metal
atom.

   /

alkali blue

  5:58 PM    Anonymous

alkali blue [ORG CHEM] The sodium salt of triphenylrosanilinesulfonic acid; used as
an indicator.

   /

alkali alcoholate

  5:57 PM    Anonymous

alkali alcoholate [ORG CHEM] A compound formed from an alcohol and an alkali metal
base; the alkali metal replaces the hydrogen in the hydroxyl group.

   /

alkali-aggregate reaction

  5:57 PM    Anonymous

alkali-aggregate reaction [CHEM] The chemical reaction of an aggregate with the alkali
in a cement, resulting in a weakening of the concrete.

   /

alkali

  5:56 PM    Anonymous

alkali [CHEM] Any compound having highly basic qualities.

   /

alkalescence

  5:56 PM    Anonymous

alkalescence [CHEM] The property of a substance that is alkaline, that is, having a
pH greater than 7.

   /

alizarin

  5:53 PM    Anonymous

alizarin [ORG CHEM]C14H6O2(OH)2 An orange crystalline compound, insoluble in cold
water; made synthetically from anthraquinone; used in the manufacture of dyes and
red pigments.

   /

aliquot

  5:52 PM    Anonymous

aliquot [CHEM] A part of a sample that has been divided into exactly equal parts with
no remainder.

   /

aliquant

  5:52 PM    Anonymous

aliquant [CHEM] A part of a sample that has been divided into a set of equal parts
plus a smaller remainder part.

   /

aliphatic series

  5:51 PM    Anonymous

aliphatic series [ORG CHEM] A series of open-chained carbon-hydrogen compounds;
the two major classes are the series with saturated bonds and with the unsaturated.

   /

aliphatic polyene compound

  5:50 PM    Anonymous

aliphatic polyene compound [ORG CHEM] Any unsaturated aliphatic or alicyclic com-
pound with more than four carbons in the chain and with at least two double bonds;
for example, hexadiene.

   /

7.7.11

aliphatic

  10:05 PM    Anonymous

aliphatic [ORG CHEM] Of or pertaining to any organic compound of hydrogen and carbon
characterized by a straight chain of the carbon atoms; three subgroups of such
compounds are alkanes, alkenes, and alkynes.

   /

alicyclic

  10:05 PM    Anonymous

alicyclic [ORG CHEM] 1. Having the properties of both aliphatic and cyclic substances.
2. Referring to a class of saturated hydrocarbon compounds whose structures contain
one ring. Also known as cycloaliphatic; cycloalkane.Any one of the compounds of
the alicyclic class. Also known as cyclane.

   /

alginic acid

  10:03 PM    Anonymous

alginic acid [ORG CHEM](C6H8O6)n An insoluble colloidal acid obtained from brown
marine algae; it is hard when dry and absorbent when moist. Also known as algin.

   /

alfin catalyst

  10:02 PM    Anonymous

alfin catalyst [ORG CHEM] A catalyst derived from reaction of an alkali alcoholate with
an olefin halide; used to convert olefins (for example, ethylene, propylene, or butyl-
enes) into polyolefin polymers.

   /

Aldrin

  10:01 PM    Anonymous

Aldrin [ORG CHEM]C12H8Cl6 Trade name for a water-insoluble, white, crystalline com-
pound, consisting mainly of chlorinated dimethanonaphthalene; used as a pesticide.

   /

aldose

  10:01 PM    Anonymous

aldose [ORG CHEM] A class of monosaccharide sugars; the molecule contains an alde-
hyde group.

   /

aldol condensation

  9:55 PM    Anonymous

aldol condensation [ORG CHEM] Formation of a -hydroxycarbonyl compound by the
condensation of an aldehyde or a ketone in the presence of an acid or base catalyst.
Also known as aldol reaction.

   /

aldol

  9:54 PM    Anonymous

aldol [ORG CHEM]CH3CH(OH)CH2CHO A colorless, thick liquid with a boiling point of
83 C; used in manufacturing rubber age resistors, accelerators, and vulcanizers.

   /

aldohexose

  9:54 PM    Anonymous

aldohexose [ORG CHEM] A hexose, such as glucose or mannose, containing the alde-
hyde group.

   /

aldicarb

  9:53 PM    Anonymous

aldicarb [ORG CHEM]C7H14N2O2S A colorless, crystalline compound with a melting
point of 100 C; used as an insecticide, miticide, and nematicide to treat soil for
cotton, sugarbeets, potatoes, peanuts, and ornamentals.

   /

aldehyde polymer

  9:52 PM    Anonymous

aldehyde polymer [ORG CHEM] Any of the plastics based on aldehydes, such as formal-
dehyde, acetaldehyde, butyraldehyde, or acrylic aldehyde (acrolein). 

   /

aldehyde ammonia

  9:51 PM    Anonymous

aldehyde ammonia [ORG CHEM]CH3CHOHNH2 A white, crystalline solid with a melting
point of 97 C; soluble in water and alcohol; used in organic synthesis and as a
vulcanization accelerator.

   /

aldehyde

  9:51 PM    Anonymous

aldehyde [ORG CHEM] One of a class of organic compounds containing the CHO radical.

   /

alcosol

  9:50 PM    Anonymous

alcosol [CHEM] Mixture of an alcohol and a colloid.

   /

alcoholysis

  9:48 PM    Anonymous

alcoholysis [ORG CHEM] The breaking of a carbon-to-carbon bond by addition of an
alcohol.

   /

4.7.11

alcoholate

  11:48 AM    Anonymous

alcoholate [ORG CHEM] A compound formed by the reaction of an alcohol with an
alkali metal. Also known as alkoxide.

   /

alcohol

  11:47 AM    Anonymous

alcohol [ORG CHEM] Any member of a class of organic compounds in which a hydrogen
atom of a hydrocarbon has been replaced by a hydroxy ( OH) group.

   /

alcogel

  11:46 AM    Anonymous

alcogel [CHEM] A gel formed by an alcosol.

   /

alchemy

  11:46 AM    Anonymous

alchemy [CHEM] A speculative chemical systemhaving as its central aims the transmu-
tation of base metals to gold and the discovery of the philosopher’s stone.

   /

alanyl

  11:45 AM    Anonymous

alanyl [ORG CHEM] The radical CH3CHNH2CO ; occurs in, for example, alanyl alanine,
a dipeptide.

   /

Al

  11:44 AM    Anonymous

Al See aluminum.

   /

ajmaline

  11:44 AM    Anonymous

ajmaline [ORG CHEM]C20H26N2O2 An amber, crystalline alkaloid obtained from Rauwolfia
plants, especially R.serpentina.

   /

air slaked

  11:43 AM    Anonymous

air-slaked [CHEM] Having the property of a substance, such as lime, that has been at
least partially converted to a carbonate by exposure to air.

   /

air line

  11:42 AM    Anonymous

air line [SPECT] Lines in a spectrum due to the excitation of air molecules by spark
discharges, and not ordinarily present in arc discharges.

   /

air fuel ratio

  11:41 AM    Anonymous

air-fuel ratio [CHEM] The ratio of air to fuel by weight or volume which is significant
for proper oxidative combustion of the fuel.

   /

air deficiency

  11:36 AM    Anonymous

air deficiency [CHEM] Insufficient air in an air-fuel mixture causing either incomplete
fuel oxidation or lack of ignition.

  

air

  11:35 AM    Anonymous

air [CHEM] A predominantlymechanicalmixture of a variety of individual gases forming
the earth’s enveloping atmosphere.

   /

agostic

  11:34 AM    Anonymous

agostic [ORG CHEM] A three-center, two-electron bonding interaction in which a hydro-
gen atom is bonded to both a carbon atom and a metal atom, such as the interaction
of a CH bond and an unsaturated transition-metal compound.

   /

aging

  11:33 AM    Anonymous

aging [CHEM] All irreversible structural changes that occur in a precipitate after it has
formed.

   /

aggregation

  11:32 AM    Anonymous

aggregation [CHEM] A process that results in the formation of aggregates.

   /

aggregate

  11:31 AM    Anonymous

aggregate [CHEM] A group of atoms or molecules that are held together in any way,
for example, a micelle.

   /

agavose

  11:30 AM    Anonymous

agavose [ORG CHEM]C12H22O11 A sugar found in the juice of the agave tree; used in
medicine as a diuretic and laxative.

   /

agaric acid

  11:29 AM    Anonymous

agaric acid [ORG CHEM]C19H36(OH)(COOH)3 An acid with melting point 141 C; soluble
in water, insoluble in benzene; used as an irritant. Also known as agaricin.

   /

affinity chromatography

  11:27 AM    Anonymous

affinity chromatography [ANALY CHEM] A chromatographic technique that utilizes the
ability of biological molecules to bend to certain ligands specifically and reversibly;
used in protein biochemistry.

   /

affinity

  11:25 AM    Anonymous

affinity [CHEM] The extent to which a substance or functional group can enter into a
chemical reactionwith a given agent. Also known as chemical affinity.

   /

AES

  11:22 AM    Anonymous

AES See Auger electron spectroscopy

   /

aerosol

  11:21 AM    Anonymous

aerosol [CHEM] A suspension of small particles in a gas; the particles may be solid
or liquid or a mixture of both; aerosols are formed by the conversion of gases to
particles, the disintegration of liquids or solids, or the suspension of powdered
material.

   /

aerogel

  11:21 AM    Anonymous

aerogel [CHEM] A porous solid formed from a gel by replacing the liquid with a gas
with little change in volume so that the solid is highly porous.

   /

aeration cell

  11:20 AM    Anonymous

aeration cell [PHYS CHEM] An electrolytic cell whose electromotive force is due to
electrodes of the same material located in different concentrations of dissolved air.
Also known as oxygen cell.

   /

adsorption potential

  11:20 AM    Anonymous

adsorption potential [PHYS CHEM] A change in the chemical potential that occurs as
an ionmoves froma gas or solution phase to the surface of an adsorbent.

   /

adsorption isotherm

  11:19 AM    Anonymous

adsorption isotherm [PHYS CHEM] The relationship between the gas pressure p and
the amount w, in grams, of a gas or vapor taken up per gram of solid at a constant
temperature.

   /

adsorption isobar

  11:19 AM    Anonymous

adsorption isobar [PHYS CHEM] A graph showing how adsorption varies with some
parameter, such as temperature, while holding pressure constant.

   /

adsorption indicator

  11:16 AM    Anonymous

adsorption indicator [ANALY CHEM] An indicator used in solutions to detect slight
excess of a substance or ion; precipitate becomes colored when the indicator is
adsorbed. An example is fluorescein.

   /

adsorption complex

  11:15 AM    Anonymous

adsorption complex [CHEM] An entity consisting of an adsorbate and that portion of
the adsorbent to which it is bound.

   /

adsorption chromatography

  11:14 AM    Anonymous

adsorption chromatography [ANALY CHEM] Separation of a chemical mixture (gas or
liquid) by passing it over an adsorbent bed which adsorbs different compounds at
different rates

   /

adsorption

  11:13 AM    Anonymous

adsorption [CHEM] The surface retention of solid, liquid, or gas molecules, atoms, or
ions by a solid or liquid, as opposed to absorbtion, the penetration of substances
into the bulk of the solid or liquid.

   /

adsorbent

  11:13 AM    Anonymous

adsorbent [CHEM] A solid or liquid that adsorbs other substances; for example, char-
coal, silica, metals, water, and mercury.

   /

adsorbate

  11:12 AM    Anonymous

adsorbate [CHEM] A solid, liquid, or gas which is adsorbed as molecules, atoms, or
ions by such substances as charcoal, silica,metals, water, andmercury.

   /

adiponitrile

  11:11 AM    Anonymous

adiponitrile [ORG CHEM] NC(CH2)4CN The high-boiling liquid dinitrile of adipic acid;
used to make nylon intermediates.

   /

adipic acid

  11:10 AM    Anonymous

adipic acid [ORG CHEM] HOOC(CH2)4COOH A colorless crystalline dicarboxylic acid,
sparingly soluble in water; used in nylon manufacture.

   /

adipate

  11:10 AM    Anonymous

adipate [ORG CHEM] Salt produced by reaction of adipic acid with a basic compound.

   /

adiabatic flame temperature

  11:09 AM    Anonymous

adiabatic flame temperature [PHYS CHEM] The highest possible temperature of com-
bustion obtained under the conditions that the burning occurs in an adiabatic vessel,
that it is complete, and that dissociation does not occur.

   /

adduct

  11:08 AM    Anonymous

adduct [CHEM] 1. A chemical compound that forms from chemical addition of two
species; for example, reaction of butadiene with styrene forms an adduct, 4-phenyl-
1-cyclohexene. 2. The complex compound formed by association of an inclusion
complex.

   /

addition reaction

  11:06 AM    Anonymous

addition reaction [ORG CHEM] A type of reaction of unsaturated hydrocarbons with
hydrogen, halogens, halogen acids, and other reagents, so that no change in valency
is observed and the organic compound forms a more complex one.

   /

addition polymerization

  11:05 AM    Anonymous

addition polymerization [ORG CHEM] A reaction initiated by an anion, cation, or radical
in which a large number of monomer units are added rapidly (a chain reaction) until
terminated by some mechanism, forming a high-molecular-weight polymer in a very
short time; an example is the free-radical polymerization of propylene to polypro-
pylene.

   /

addition polymer

  11:05 AM    Anonymous

addition polymer [ORG CHEM] A polymer formed by the chain addition of unsaturated
monomer molecules, such as olefins, with one another without the formation of a
by-product, as water; examples are polyethylene, polypropylene, and polystyrene.
Also known as addition resin.

   /

addition agent

  11:04 AM    Anonymous

addition agent [PHYS CHEM] A substance added to a plating solution to change charac-
teristics of the deposited substances.

   /

adatom

  11:03 AM    Anonymous

adatom [PHYS CHEM] An atom adsorbed on a surface so that it will migrate over the
surface.

   /

1.7.11

adamsite

  7:16 PM    Anonymous

adamsite [ORG CHEM]C6H4 NH C6H4 AsCl A yellowcrystalline arsenical; used in leather
tanning and in warfare and riot control to produce skin and eye irritation, chest
distress, and nausea; U.S. Army code is DM. Also known as diphenylaminechloroar-
sine; phenarsazine chloride.

   /

adamantane

  7:16 PM    Anonymous

adamantane [ORG CHEM]AC10H16 alicyclic hydrocarbon whose structure has the same
arrangement of carbon atoms as does the basic unit of the diamond lattice.

   /

acyloin condensation

  7:15 PM    Anonymous

acyloin condensation [ORG CHEM] The reaction of an aliphatic ester with metallic
sodium to form intermediates converted by hydrolysis into aliphatic -hydroxy-
ketones called acyloins.

   /

acyloin

  7:14 PM    Anonymous

acyloin [ORG CHEM] An organic compound that may be synthesized by condensation
of aldehydes; an example is benzoin, C6H5COCHOHC6H5.

   /

acylnitrene

  7:14 PM    Anonymous

acylnitrene [ORG CHEM] A nitrene in which the nitrogen is covalently bonded to an
acyl group.

   /

acyl halide

  7:13 PM    Anonymous

acyl halide [ORG CHEM] One of a large group of organic substances containing the
halocarbonyl group; for example, acyl fluoride.

   /

acylcarbene

  7:12 PM    Anonymous

acylcarbene [ORG CHEM] A carbene radical in which at least one of the groups attached
to the divalent carbon is an acyl group; for example, acetylcarbene.

   /

acylation

  7:11 PM    Anonymous

acylation [ORG CHEM] Any process whereby the acyl group is incorporated into a mole-
cule by substitution.

   /

acyl

  7:10 PM    Anonymous

acyl [ORG CHEM] A radical formed from an organic acid by removal of a hydroxyl group;
the general formula is RCO, where Rmay be aliphatic, alicyclic, or aromatic.

   /

acyclic compound

  7:10 PM    Anonymous

acyclic compound [ORG CHEM] A chemical compound with an open-chain molecular
structure rather than a ring-shaped structure; for example, the alkane series.

   /

activity series

  7:08 PM    Anonymous

activity series [CHEM] A series of elements that have similar properties—for example,
metals—arranged in descending order of chemical activity.

   /

activity coefficient

  7:08 PM    Anonymous

activity coefficient [PHYS CHEM] A characteristic of a quantity expressing the deviation
of a solution from ideal thermodynamic behavior; often used in connection with
electrolytes.

   /

activity

  7:07 PM    Anonymous

activity [PHYS CHEM] A thermodynamic function that correlates changes in the chemical
potential with changes in experimentally measurable quantities, such as concentra-
tions or partial pressures, through relations formally equivalent to those for ideal
systems.

   /

active solid

  7:07 PM    Anonymous

active solid [CHEM] A porous solid possessing adsorptive properties and used for
chromatographic separations.

   /

active site

  7:06 PM    Anonymous

active site [CHEM] The effective site at which a given heterogeneous catalytic reaction
can take place. Also known as active center.

   /

active center

  7:05 PM    Anonymous

active center [CHEM] 1. Any one of the points on the surface of a catalyst at which
the chemical reaction is initiated or takes place. 2. See active site.

   /

activator

  7:05 PM    Anonymous

activator [CHEM] 1. A substance that increases the effectiveness of a rubber vulcaniza-
tion accelerator; for example, zinc oxide or litharge. 2. A trace quantity of a substance
that imparts luminescence to crystals; for example, silver or copper in zinc sulfide
or cadmium sulfide pigments.

   /

activation energy

  7:04 PM    Anonymous

activation energy [PHYS CHEM] The energy, in excess over the ground state, which must
be added to an atomic or molecular system to allow a particular process to take
place.

   /

activation

  7:03 PM    Anonymous

activation [CHEM] Treatment of a substance by heat, radiation, or activating reagent
to produce a more complete or rapid chemical or physical change.

   /

activated complex

  6:56 PM    Anonymous

activated complex [PHYS CHEM] An energetically excited state which is intermediate
between reactants and products in a chemical reaction. Also known as transition
state.

   /

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