Hawley’s
`
`Condensed Chemical
`
`Dictionary
`
`THIRTEENTH EDITION
`
`Revised by
`
`Richard J. Lewis, Sr.
`
`JSF
`
`02- 56
`
`JOHN WILEY & SONS, INC.
`NewYork 0 Chichester - Weinheim 0 Brisbane - Singapore 0 Toronto
`
`Depomed Exhibit 2026
`
`

`
`This text is printed on acid-free paper.
`
`Copyright © 1997 by John Wiley & Sons, Inc.
`
`No part of this publication may be reproduced, stored in a retrieval system, or
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`Library of Congress Cataloging-imPublication Data
`
`Condensed chemical dictionary.
`Hawley's condensed chemical dictionary.-l3th edirevised by
`Richard J. Lewis. Sr.
`p.
`cm.
`ISBN 0-471-29205-2 ihardcover)
`
`1. Chemistry-Dictionaries.
`Il. Lewis. Richard 1.. Sr.
`QD5.C5
`I997
`540'.3—dc2l
`
`97-35762
`CIP
`
`I. 1-lawley. Gessner Goodrich, 1905-1983.
`111. Title.
`
`Printed in the United States of America
`
`109876
`
`
`
`

`
`659
`
`LEAD AZIDE
`
`LCL. Abbreviation for “less than carload lot,"
`used by shippers, traffic managers, railroads, etc.
`
`(lethal dose 50%). That quantity of a sub-
`LD50.
`stance necessary to kill 50% of exposed animals in
`laboratory tests within a specified time. A substance
`having an oral LD5,, of less than 400 mg/kg of body
`weight is considered to be highly toxic.
`
`LDPE. Abbreviation for low-density polyethyl-
`ene.
`
`leaching.
`
`See solvent extraction.
`
`(from Latin plumbum).
`lead.
`CAS: 7439-92-1. Pb. Metallic element of atomic
`number 82, group IVA of the periodic table, aw
`207.2, valences = 2,4, four stable isotopes. The
`isotopes are the end products of the disintegration
`of three series of natural radioactive elements ura-
`nium (206), thorium (208), and actinium (207).
`Properties: Heavy, ductile, soft, gray solid. D 1 1.35,
`mp 327.4C, bp 1755C. Soluble in dilute nitric acid;
`insoluble in water but dissolves slowly in water
`containing a weak acid. Resists corrosion; relatively
`impenetrable to radiation. Poor electrical conduc-
`tor, good sound and vibration absorber. Noncom-
`bustible.
`Occurrence: U.S., Mexico, Canada, South America,
`Australia, Africa, Europe.
`Derivation: Roasting and reduction of galena (lead
`sulfide), anglesite (lead sulfate), and cerussite (lead
`carbonate). Also from scrap.
`Method of purification: Desilvering (Parkes pro-
`cess), electrolytic refining (Betts process), pyro-
`metallurgical refining (Harris process). Bismuth is
`removed by Betterton-Kroll process.
`Grade: High purity (less than 10 ppm impurity),
`pure (99.9+%), powdered (99% pure), pig lead,
`paste.
`Available forms: Ingots, sheet, pipe, shot, buckles
`or straps, grids, rod, wire, etc.; paste; powder; sin-
`gle crystals.
`Hazard: Toxic by ingestion and inhalation of dust
`or fume. TLV (Pb): (fumes and dusts and inorganic
`compounds) 0.15 mg/m3 of air. For ambient air the
`EPA standard is 1.5 itg/m3. A cumulative poison.
`FDA regulations require zero lead content in foods
`and less than 0.05% in house paints.
`Use: Storage batteries, tetraethyllead (gasoline ad-
`ditive), radiation shielding, cable covering, ammu-
`nition, chemical reaction equipment (piping, tank
`linings, etc.), solder and fusible alloys, type metal,
`vibration damping in heavy construction, foil, Bab-
`bitt and other bearing alloys.
`For further information, refer to Lead Industries As-
`sociation, 292 Madison Ave., New York, NY
`10017.
`
`(sugar of lead).
`lead acetate.
`CAS: 301-04-2. Pb(C,H,o,,),-3H,o.
`
`Properties: White crystals or flakes (commercial
`grades are frequently brown or gray lumps); sweet-
`ish taste. D 2.50, mp loses water at 75C, at 200C
`decomposes, hp (anhydrous) 280C. Absorbs carbon
`dioxide when exposed to air, becoming insoluble in
`water. Soluble in water; slightly soluble in alcohol;
`freeiy soluble in glycerol. Combustible.
`Derivation: By the action of acetic acid on iithargc
`or thin lead plates.
`Grade: Powdered, granular, crystals, flakes, CP.
`Hazard: Toxic by ingestion, inhalation, and skin ab-
`sorption; use may be restricted.
`Use: Dyeing of textiles, waterproofing, varnishes,
`lead driers, chrome pigments, gold cyanidation pro-
`cess, insecticide, antifouling paints, analytical re-
`agent, hair dye.
`
`lead alkyl, mixed. A mixture containing various
`methyl and ethyl derivatives of tetraethyi lead and
`tetramethyl lead. Thus, methyl
`triethyl
`lead, di-
`methyl diethyl lead, and ethyl trimethyl lead may
`all be present with or without tetraethyi and tetra-
`methyl lead.
`Hazard: Toxic by ingestion and skin absorption.
`Use: Antiknock agents in aviation gasoline.
`
`(Naples yellow; antimony yel-
`
`lead antimonate.
`low). Pb3(SbO4)2.
`Properties: Orange-yellow powder. D 6.58 (20C).
`Insoluble in water. Noncombustible.
`Derivation; Interaction of solutions of lead nitrate
`
`and potassium antimonate, concentration, and crys~
`taliization.
`
`Hazard: Toxic by inhalation. TLV (Pb): 0.15 mg/m3
`of air.
`
`Use: Staining glass, crockery, and porcelain.
`
`(lead orthoarsenate).
`lead arsenate.
`CAS: 7784-40-9. Pb_,(As0,)2.
`Properties: White crystals. D 5.8, mp 1042C (de-
`composes). Soluble in nitric acid: insoluble in wa-
`ter.
`
`Derivation: By the action of a soluble lead salt on
`a solution of sodium arsenate, concentration, and
`crystallization.
`Hazard: Highly toxic. TLV: 0.15 mg/m3 of air, a
`carcinogen.
`Use: Insecticide, herbicide.
`
`lead arsenite.
`CAS: 10031-13-7. I-‘b(AsO,),.
`Properties: White powder. D 5.85. Soluble in nitric
`acid; insoluble in water.
`Hazard: Highly toxic.
`Use: Insecticide.
`
`lead azide.
`CAS: 13424-46-9. Pb(N,),.
`Properties: Colorless, very sensitive needles. An
`initiating explosive. Should always be handled sub-
`merged in water.
`
`

`
`._,_,_._,_E1
`
`1035
`
`SOLVENT EXTRACTION
`
`pends on their limits of solution. The solubility of
`one substance in another is the maximum amount
`that can be dissolved at a given temperature and
`pressure. A solution containing such a maximum
`amount is saturated. A state of supersaturation can
`be created, but such solutions are unstable and may
`precipitate spontaneously.
`
`solutrope. A ternary mixture having two liquid
`phases between which one component is distributed
`in an apparent ratio varying with concentration
`from less than 1 to greater than 1. In other words,
`the solute may be selectively dissolved in one
`or the other of the phases or solvents, depending on
`the concentration. This phenomenon has been com-
`pared to azeotropic behavior.
`
`In the parlance of colloid chemistry, the
`solvation.
`adsorption of a microlayer or film of water or other
`solvent on individual dispersed particles of a solu-
`tion or dispersion. The term solvated hulls has been
`used to describe such particles. It is also applied to
`the action of plasticizers on resin dispersions in
`plastisols.
`See hydration (2).
`
`(ammonia soda process). Manu-
`Solvay process.
`facture of sodium carbonate (soda ash, Na2CO3)
`from salt, ammonia, carbon dioxide, and limestone
`by an ingenious sequence of reactions involving re-
`covery and reuse of practically all the ammonia and
`part of the carbon dioxide. Limestone is heated to
`produce lime and carbon dioxide. The latter is dis-
`solved in water containing the ammonia and salt,
`with resultant precipitation of sodium bicarbonate.
`This is separated by filtration, dried, and heated to
`form normal sodium carbonate. The liquor from the
`bicarbonate filtration is heated and treated with lime
`
`to regenerate the ammonia. Calcium chloride is a
`major by-product.
`Note: Because this process requires much energy
`and pollutes streams and rivers with chloride efflu-
`ent, many plants using it have closed, production
`being obtained from the natural deposits in the
`western U.S.
`
`“Solvenol” [Aqualon]. TM for a group of
`monocyclic terpene hydrocarbons with minor
`amounts of terpene alcohols and ketones.
`Use: General solvent, rubber reclaiming.
`
`solvent. A substance capable of dissolving another
`substance (solute) to form a uniformly dispersed
`mixture (solution) at the molecular or ionic size
`level. Solvents are either polar (high dielectric con-
`stant) or nonpolar (low dielectric constant). Water,
`the most common of all solvents, is strongly polar
`(dielectric constant 81), but hydrocarbon solvents
`are nonpolar. Aromatic hydrocarbons have higher
`solvent power than aliphatics (alcohols). Other or-
`ganic solvent groups are esters, ethers, ketones,
`amines, and nitrated and chlorinated hydrocarbons.
`
`The chief uses of organic solvents are in the coat-
`ings field (paints, varnishes, and lacquers), indus-
`trial cleaners, printing inks, extractive processes,
`and pharmaceuticals. Since many solvents are flam-
`mable and toxic to varying degrees, they contribute
`to air pollution and fire hazards. For this reason
`their use in coatings and cleaners has declined in
`recent years.
`See individual compounds.
`
`solvent, aprotic. A solvent that cannot act as a
`proton acceptor or donor, i.e., as an acid or base.
`
`solvent drying. Removal of water from metal sur-
`faces by means of a solvent that displaces it pref-
`erentially, as on precision equipment, electronic
`components, etc. Examples of solvents used are ac-
`etone,
`1,1,2-trichloro-l,2,2—trilluorethane, 1,1,1-
`trichloroethane.
`
`solvent dye.
`
`See dye, solvent.
`
`solvent extraction. A separation operation that
`may involve three types of mixture: (1) a mixture
`composed of two or more solids, such as a metallic
`ore; (2) a mixture composed of a solid and a liquid;
`(3) a mixture of two or more liquids. One or more
`components of such mixture are removed (ex-
`tracted) by exposing the mixture to the action of a
`solvent in which the component to be removed is
`soluble. If the mixture consists of two or more so]-
`ids, extraction is performed by percolation of an
`appropriate solvent through it. This procedure is
`also called leaching, especially if the solvent is wa-
`ter; coffee making is an example. Synthetic fuels
`can be made from coal by extraction with a coal-
`derived solvent followed by hydrogenation.
`In liquid—liquid extraction one or more compo-
`nents are removed from a liquid mixture by intimate
`contact with a second liquid that is itself nearly in-
`soluble in the first liquid and dissolves the impu-
`rities and not the substance that is to be purified. In
`other cases the second liquid may dissolve, i.e., ex-
`tract from the first liquid, the component that is to
`be purified, and leave associated impurities in the
`first liquid. liquid—liquid extraction may be carried
`out by simply mixing the two liquids with agitation
`and then allowing them to separate by standing. It
`is often economical to use counter-current extrac-
`
`tion, in which the two immiscible liquids are caused
`to flow past or through one another in opposite di-
`rections. Thus fine droplets of heavier liquid can be
`caused to pass downward through the lighter liquid
`in a vertical tube or tower.
`
`The solvents used vary with the nature of the prod-
`ucts involved. Widely used are water, hexane, ace-
`tone, isopropyl alcohol, furfural, xylene, liquid sul-
`fur dioxide,
`and tributyl phosphate. Solvent
`extraction is an important method of both produc-
`ing and purifying such products as lubricating and
`vegetable oils, pharmaceuticals, and nonferrous
`metals.