In chemistry and thermodynamics, the standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements in their reference state, with all substances in their standard states. The standard pressure value p⦡ = 105 Pa (= 100 kPa = 1 bar) is recommended by IUPAC, although prior to 1982 the value 1.00 atm (101.325 kPa) was used.[1] There is no standard temperature. Its symbol is ΞfH⦡. The superscript Plimsoll on this symbol indicates that the process has occurred under standard conditions at the specified temperature (usually 25 Β°C or 298.15 K).
Standard states are defined for various types of substances. For a gas, it is the hypothetical state the gas would assume if it obeyed the ideal gas equation at a pressure of 1 bar. For a gaseous or solid solute present in a diluted ideal solution, the standard state is the hypothetical state of concentration of the solute of exactly one mole per liter (1 M) at a pressure of 1 bar extrapolated from infinite dilution. For a pure substance or a solvent in a condensed state (a liquid or a solid) the standard state is the pure liquid or solid under a pressure of 1 bar.
For elements that have multiple allotropes, the reference state usually is chosen to be the form in which the element is most stable under 1 bar of pressure. One exception is phosphorus, for which the most stable form at 1 bar is black phosphorus, but white phosphorus is chosen as the standard reference state for zero enthalpy of formation.[2]
For example, the standard enthalpy of formation of carbon dioxide is the enthalpy of the following reaction under the above conditions:
All elements are written in their standard states, and one mole of product is formed. This is true for all enthalpies of formation.
The standard enthalpy of formation is measured in units of energy per amount of substance, usually stated in kilojoule per mole (kJ molβ1), but also in kilocalorie per mole, joule per mole or kilocalorie per gram (any combination of these units conforming to the energy per mass or amount guideline).
All elements in their reference states (oxygen gas, solid carbon in the form of graphite, etc.) have a standard enthalpy of formation of zero, as there is no change involved in their formation.
The formation reaction is a constant pressure and constant temperature process. Since the pressure of the standard formation reaction is fixed at 1 bar, the standard formation enthalpy or reaction heat is a function of temperature. For tabulation purposes, standard formation enthalpies are all given at a single temperature: 298 K, represented by the symbol ΞfH⦡
298 K.
Hess's law
For many substances, the formation reaction may be considered as the sum of a number of simpler reactions, either real or fictitious. The enthalpy of reaction can then be analyzed by applying Hess's Law, which states that the sum of the enthalpy changes for a number of individual reaction steps equals the enthalpy change of the overall reaction. This is true because enthalpy is a state function, whose value for an overall process depends only on the initial and final states and not on any intermediate states. Examples are given in the following sections.
Ionic compounds: BornβHaber cycle
For ionic compounds, the standard enthalpy of formation is equivalent to the sum of several terms included in the BornβHaber cycle. For example, the formation of lithium fluoride,
may be considered as the sum of several steps, each with its own enthalpy (or energy, approximately):
- Hsub, the standard enthalpy of atomization (or sublimation) of solid lithium.
- IELi, the first ionization energy of gaseous lithium.
- B(FβF), the standard enthalpy of atomization (or bond energy) of fluorine gas.
- EAF, the electron affinity of a fluorine atom.
- UL, the lattice energy of lithium fluoride.
The sum of these enthalpies give the standard enthalpy of formation (ΔfH) of lithium fluoride:
In practice, the enthalpy of formation of lithium fluoride can be determined experimentally, but the lattice energy cannot be measured directly. The equation is therefore rearranged to evaluate the lattice energy:[3]
Organic compounds
The formation reactions for most organic compounds are hypothetical. For instance, carbon and hydrogen will not directly react to form methane (CH4), so that the standard enthalpy of formation cannot be measured directly. However the standard enthalpy of combustion is readily measurable using bomb calorimetry. The standard enthalpy of formation is then determined using Hess's law. The combustion of methane:
is equivalent to the sum of the hypothetical decomposition into elements followed by the combustion of the elements to form carbon dioxide (CO2) and water (H2O):
Applying Hess's law,
Solving for the standard of enthalpy of formation,
The value of is determined to be β74.8 kJ/mol. The negative sign shows that the reaction, if it were to proceed, would be exothermic; that is, methane is enthalpically more stable than hydrogen gas and carbon.
It is possible to predict heats of formation for simple unstrained organic compounds with the heat of formation group additivity method.
Use in calculation for other reactions
The standard enthalpy change of any reaction can be calculated from the standard enthalpies of formation of reactants and products using Hess's law. A given reaction is considered as the decomposition of all reactants into elements in their standard states, followed by the formation of all products. The heat of reaction is then minus the sum of the standard enthalpies of formation of the reactants (each being multiplied by its respective stoichiometric coefficient, Ξ½) plus the sum of the standard enthalpies of formation of the products (each also multiplied by its respective stoichiometric coefficient), as shown in the equation below:[4]
If the standard enthalpy of the products is less than the standard enthalpy of the reactants, the standard enthalpy of reaction is negative. This implies that the reaction is exothermic. The converse is also true; the standard enthalpy of reaction is positive for an endothermic reaction. This calculation has a tacit assumption of ideal solution between reactants and products where the enthalpy of mixing is zero.
For example, for the combustion of methane, :
However is an element in its standard state, so that , and the heat of reaction is simplified to
which is the equation in the previous section for the enthalpy of combustion .
Key concepts for enthalpy calculations
- When a reaction is reversed, the magnitude of ΞH stays the same, but the sign changes.
- When the balanced equation for a reaction is multiplied by an integer, the corresponding value of ΞH must be multiplied by that integer as well.
- The change in enthalpy for a reaction can be calculated from the enthalpies of formation of the reactants and the products
- Elements in their standard states make no contribution to the enthalpy calculations for the reaction, since the enthalpy of an element in its standard state is zero. Allotropes of an element other than the standard state generally have non-zero standard enthalpies of formation.
Examples: standard enthalpies of formation at 25 Β°C
Thermochemical properties of selected substances at 298.15 K and 1 atm
Inorganic substances
Species | Phase | Chemical formula | ΞfH⦡ /(kJ/mol) |
---|---|---|---|
Aluminium | Solid | Al | 0 |
Aluminium chloride | Solid | AlCl3 | β705.63 |
Aluminium oxide | Solid | Al2O3 | β1675.5 |
Aluminium hydroxide | Solid | Al(OH)3 | β1277 |
Aluminium sulphate | Solid | Al2(SO4)3 | β3440 |
Barium chloride | Solid | BaCl2 | β858.6 |
Barium carbonate | Solid | BaCO3 | β1216 |
Barium hydroxide | Solid | Ba(OH)2 | β944.7 |
Barium oxide | Solid | BaO | β548.1 |
Barium sulfate | Solid | BaSO4 | β1473.3 |
Beryllium | Solid | Be | 0 |
Beryllium hydroxide | Solid | Be(OH)2 | β903 |
Beryllium oxide | Solid | BeO | β609.4 |
Boron trichloride | Solid | BCl3 | β402.96 |
Bromine | Liquid | Br2 | 0 |
Bromide ion | Aqueous | Brβ | β121 |
Bromine | Gas | Br | 111.884 |
Bromine | Gas | Br2 | 30.91 |
Bromine trifluoride | Gas | BrF3 | β255.60 |
Hydrogen bromide | Gas | HBr | β36.29 |
Cadmium | Solid | Cd | 0 |
Cadmium oxide | Solid | CdO | β258 |
Cadmium hydroxide | Solid | Cd(OH)2 | β561 |
Cadmium sulfide | Solid | CdS | β162 |
Cadmium sulfate | Solid | CdSO4 | β935 |
Caesium | Solid | Cs | 0 |
Caesium | Gas | Cs | 76.50 |
Caesium | Liquid | Cs | 2.09 |
Caesium(I) ion | Gas | Cs+ | 457.964 |
Caesium chloride | Solid | CsCl | β443.04 |
Calcium | Solid | Ca | 0 |
Calcium | Gas | Ca | 178.2 |
Calcium(II) ion | Gas | Ca2+ | 1925.90 |
Calcium(II) ion | Aqueous | Ca2+ | β542.7 |
Calcium carbide | Solid | CaC2 | β59.8 |
Calcium carbonate (Calcite) | Solid | CaCO3 | β1206.9 |
Calcium chloride | Solid | CaCl2 | β795.8 |
Calcium chloride | Aqueous | CaCl2 | β877.3 |
Calcium phosphate | Solid | Ca3(PO4)2 | β4132 |
Calcium fluoride | Solid | CaF2 | β1219.6 |
Calcium hydride | Solid | CaH2 | β186.2 |
Calcium hydroxide | Solid | Ca(OH)2 | β986.09 |
Calcium hydroxide | Aqueous | Ca(OH)2 | β1002.82 |
Calcium oxide | Solid | CaO | β635.09 |
Calcium sulfate | Solid | CaSO4 | β1434.52 |
Calcium sulfide | Solid | CaS | β482.4 |
Wollastonite | Solid | CaSiO3 | β1630 |
Carbon (Graphite) | Solid | C | 0 |
Carbon (Diamond) | Solid | C | 1.9 |
Carbon | Gas | C | 716.67 |
Carbon dioxide | Gas | CO2 | β393.509 |
Carbon disulfide | Liquid | CS2 | 89.41 |
Carbon disulfide | Gas | CS2 | 116.7 |
Carbon monoxide | Gas | CO | β110.525 |
Carbonyl chloride (Phosgene) | Gas | COCl2 | β218.8 |
Carbon dioxide (unβionized) | Aqueous | CO2(aq) | β419.26 |
Bicarbonate ion | Aqueous | HCO3β | β689.93 |
Carbonate ion | Aqueous | CO32β | β675.23 |
Monatomic chlorine | Gas | Cl | 121.7 |
Chloride ion | Aqueous | Clβ | β167.2 |
Chlorine | Gas | Cl2 | 0 |
Chromium | Solid | Cr | 0 |
Copper | Solid | Cu | 0 |
Copper(II) bromide | Solid | CuBr2 | β138.490 |
Copper(II) chloride | Solid | CuCl2 | β217.986 |
Copper(II) oxide | Solid | CuO | β155.2 |
Copper(II) sulfate | Aqueous | CuSO4 | β769.98 |
Fluorine | Gas | F2 | 0 |
Monatomic hydrogen | Gas | H | 218 |
Hydrogen | Gas | H2 | 0 |
Water | Gas | H2O | β241.818 |
Water | Liquid | H2O | β285.8 |
Hydrogen ion | Aqueous | H+ | 0 |
Hydroxide ion | Aqueous | OHβ | β230 |
Hydrogen peroxide | Liquid | H2O2 | β187.8 |
Phosphoric acid | Liquid | H3PO4 | β1288 |
Hydrogen cyanide | Gas | HCN | 130.5 |
Hydrogen bromide | Liquid | HBr | β36.3 |
Hydrogen chloride | Gas | HCl | β92.30 |
Hydrogen chloride | Aqueous | HCl | β167.2 |
Hydrogen fluoride | Gas | HF | β273.3 |
Hydrogen iodide | Gas | HI | 26.5 |
Iodine | Solid | I2 | 0 |
Iodine | Gas | I2 | 62.438 |
Iodine | Aqueous | I2 | 23 |
Iodide ion | Aqueous | Iβ | β55 |
Iron | Solid | Fe | 0 |
Iron carbide (Cementite) | Solid | Fe3C | 5.4 |
Iron(II) carbonate (Siderite) | Solid | FeCO3 | β750.6 |
Iron(III) chloride | Solid | FeCl3 | β399.4 |
Iron(II) oxide (WΓΌstite) | Solid | FeO | β272 |
Iron(II,III) oxide (Magnetite) | Solid | Fe3O4 | β1118.4 |
Iron(III) oxide (Hematite) | Solid | Fe2O3 | β824.2 |
Iron(II) sulfate | Solid | FeSO4 | β929 |
Iron(III) sulfate | Solid | Fe2(SO4)3 | β2583 |
Iron(II) sulfide | Solid | FeS | β102 |
Pyrite | Solid | FeS2 | β178 |
Lead | Solid | Pb | 0 |
Lead dioxide | Solid | PbO2 | β277 |
Lead sulfide | Solid | PbS | β100 |
Lead sulfate | Solid | PbSO4 | β920 |
Lead(II) nitrate | Solid | Pb(NO3)2 | β452 |
Lead(II) sulfate | Solid | PbSO4 | β920 |
Lithium fluoride | Solid | LiF | β616.93 |
Magnesium | Solid | Mg | 0 |
Magnesium ion | Aqueous | Mg2+ | β466.85 |
Magnesium carbonate | Solid | MgCO3 | β1095.797 |
Magnesium chloride | Solid | MgCl2 | β641.8 |
Magnesium hydroxide | Solid | Mg(OH)2 | β924.54 |
Magnesium hydroxide | Aqueous | Mg(OH)2 | β926.8 |
Magnesium oxide | Solid | MgO | β601.6 |
Magnesium sulfate | Solid | MgSO4 | β1278.2 |
Manganese | Solid | Mn | 0 |
Manganese(II) oxide | Solid | MnO | β384.9 |
Manganese(IV) oxide | Solid | MnO2 | β519.7 |
Manganese(III) oxide | Solid | Mn2O3 | β971 |
Manganese(II,III) oxide | Solid | Mn3O4 | β1387 |
Permanganate | Aqueous | MnOβ 4 |
β543 |
Mercury(II) oxide (red) | Solid | HgO | β90.83 |
Mercury sulfide (red, cinnabar) | Solid | HgS | β58.2 |
Nitrogen | Gas | N2 | 0 |
Ammonia (ammonium hydroxide) | Aqueous | NH3 (NH4OH) | β80.8 |
Ammonia | Gas | NH3 | β46.1 |
Ammonium nitrate | Solid | NH4NO3 | β365.6 |
Ammonium chloride | Solid | NH4Cl | β314.55 |
Nitrogen dioxide | Gas | NO2 | 33.2 |
Hydrazine | Gas | N2H4 | 95.4 |
Hydrazine | Liquid | N2H4 | 50.6 |
Nitrous oxide | Gas | N2O | 82.05 |
Nitric oxide | Gas | NO | 90.29 |
Dinitrogen tetroxide | Gas | N2O4 | 9.16 |
Dinitrogen pentoxide | Solid | N2O5 | β43.1 |
Dinitrogen pentoxide | Gas | N2O5 | 11.3 |
Nitric acid | Aqueous | HNO3 | β207 |
Monatomic oxygen | Gas | O | 249 |
Oxygen | Gas | O2 | 0 |
Ozone | Gas | O3 | 143 |
White phosphorus | Solid | P4 | 0 |
Red phosphorus | Solid | P | β17.4[5] |
Black phosphorus | Solid | P | β39.3[5] |
Phosphorus trichloride | Liquid | PCl3 | β319.7 |
Phosphorus trichloride | Gas | PCl3 | β278 |
Phosphorus pentachloride | Solid | PCl5 | β440 |
Phosphorus pentachloride | Gas | PCl5 | β321 |
Phosphorus pentoxide | Solid | P2O5 | β1505.5[6] |
Potassium bromide | Solid | KBr | β392.2 |
Potassium carbonate | Solid | K2CO3 | β1150 |
Potassium chlorate | Solid | KClO3 | β391.4 |
Potassium chloride | Solid | KCl | β436.68 |
Potassium fluoride | Solid | KF | β562.6 |
Potassium oxide | Solid | K2O | β363 |
Potassium nitrate | Solid | KNO3 | β494.5 |
Potassium perchlorate | Solid | KClO4 | β430.12 |
Silicon | Gas | Si | 368.2 |
Silicon carbide | Solid | SiC | β74.4,[7] β71.5[8] |
Silicon tetrachloride | Liquid | SiCl4 | β640.1 |
Silica (Quartz) | Solid | SiO2 | β910.86 |
Silver bromide | Solid | AgBr | β99.5 |
Silver chloride | Solid | AgCl | β127.01 |
Silver iodide | Solid | AgI | β62.4 |
Silver oxide | Solid | Ag2O | β31.1 |
Silver sulfide | Solid | Ag2S | β31.8 |
Sodium | Solid | Na | 0 |
Sodium | Gas | Na | 107.5 |
Sodium bicarbonate | Solid | NaHCO3 | β950.8 |
Sodium carbonate | Solid | Na2CO3 | β1130.77 |
Sodium chloride | Aqueous | NaCl | β407.27 |
Sodium chloride | Solid | NaCl | β411.12 |
Sodium chloride | Liquid | NaCl | β385.92 |
Sodium chloride | Gas | NaCl | β181.42 |
Sodium chlorate | Solid | NaClO3 | β365.4 |
Sodium fluoride | Solid | NaF | β569.0 |
Sodium hydroxide | Aqueous | NaOH | β469.15 |
Sodium hydroxide | Solid | NaOH | β425.93 |
Sodium hypochlorite | Solid | NaOCl | β347.1 |
Sodium nitrate | Aqueous | NaNO3 | β446.2 |
Sodium nitrate | Solid | NaNO3 | β424.8 |
Sodium oxide | Solid | Na2O | β414.2 |
Sulfur (monoclinic) | Solid | S8 | 0.3 |
Sulfur (rhombic) | Solid | S8 | 0 |
Hydrogen sulfide | Gas | H2S | β20.63 |
Sulfur dioxide | Gas | SO2 | β296.84 |
Sulfur trioxide | Gas | SO3 | β395.7 |
Sulfuric acid | Liquid | H2SO4 | β814 |
Titanium | Gas | Ti | 468 |
Titanium tetrachloride | Gas | TiCl4 | β763.2 |
Titanium tetrachloride | Liquid | TiCl4 | β804.2 |
Titanium dioxide | Solid | TiO2 | β944.7 |
Zinc | Gas | Zn | 130.7 |
Zinc chloride | Solid | ZnCl2 | β415.1 |
Zinc oxide | Solid | ZnO | β348.0 |
Zinc sulfate | Solid | ZnSO4 | β980.14 |
Aliphatic hydrocarbons
Formula | Name | ΞfH⦡ /(kcal/mol) | ΞfH⦡ /(kJ/mol) |
---|---|---|---|
Straight-chain | |||
CH4 | Methane | β17.9 | β74.9 |
C2H6 | Ethane | β20.0 | β83.7 |
C2H4 | Ethylene | 12.5 | 52.5 |
C2H2 | Acetylene | 54.2 | 226.8 |
C3H8 | Propane | β25.0 | β104.6 |
C4H10 | n-Butane | β30.0 | β125.5 |
C5H12 | n-Pentane | β35.1 | β146.9 |
C6H14 | n-Hexane | β40.0 | β167.4 |
C7H16 | n-Heptane | β44.9 | β187.9 |
C8H18 | n-Octane | β49.8 | β208.4 |
C9H20 | n-Nonane | β54.8 | β229.3 |
C10H22 | n-Decane | β59.6 | β249.4 |
C4 Alkane branched isomers | |||
C4H10 | Isobutane (methylpropane) | β32.1 | β134.3 |
C5 Alkane branched isomers | |||
C5H12 | Neopentane (dimethylpropane) | β40.1 | β167.8 |
C5H12 | Isopentane (methylbutane) | β36.9 | β154.4 |
C6 Alkane branched isomers | |||
C6H14 | 2,2-Dimethylbutane | β44.5 | β186.2 |
C6H14 | 2,3-Dimethylbutane | β42.5 | β177.8 |
C6H14 | 2-Methylpentane (isohexane) | β41.8 | β174.9 |
C6H14 | 3-Methylpentane | β41.1 | β172.0 |
C7 Alkane branched isomers | |||
C7H16 | 2,2-Dimethylpentane | β49.2 | β205.9 |
C7H16 | 2,2,3-Trimethylbutane | β49.0 | β205.0 |
C7H16 | 3,3-Dimethylpentane | β48.1 | β201.3 |
C7H16 | 2,3-Dimethylpentane | β47.3 | β197.9 |
C7H16 | 2,4-Dimethylpentane | β48.2 | β201.7 |
C7H16 | 2-Methylhexane | β46.5 | β194.6 |
C7H16 | 3-Methylhexane | β45.7 | β191.2 |
C7H16 | 3-Ethylpentane | β45.3 | β189.5 |
C8 Alkane branched isomers | |||
C8H18 | 2,3-Dimethylhexane | β55.1 | β230.5 |
C8H18 | 2,2,3,3-Tetramethylbutane | β53.9 | β225.5 |
C8H18 | 2,2-Dimethylhexane | β53.7 | β224.7 |
C8H18 | 2,2,4-Trimethylpentane (isooctane) | β53.5 | β223.8 |
C8H18 | 2,5-Dimethylhexane | β53.2 | β222.6 |
C8H18 | 2,2,3-Trimethylpentane | β52.6 | β220.1 |
C8H18 | 3,3-Dimethylhexane | β52.6 | β220.1 |
C8H18 | 2,4-Dimethylhexane | β52.4 | β219.2 |
C8H18 | 2,3,4-Trimethylpentane | β51.9 | β217.1 |
C8H18 | 2,3,3-Trimethylpentane | β51.7 | β216.3 |
C8H18 | 2-Methylheptane | β51.5 | β215.5 |
C8H18 | 3-Ethyl-3-Methylpentane | β51.4 | β215.1 |
C8H18 | 3,4-Dimethylhexane | β50.9 | β213.0 |
C8H18 | 3-Ethyl-2-Methylpentane | β50.4 | β210.9 |
C8H18 | 3-Methylheptane | β60.3 | β252.5 |
C8H18 | 4-Methylheptane | ? | ? |
C8H18 | 3-Ethylhexane | ? | ? |
C9 Alkane branched isomers (selected) | |||
C9H20 | 2,2,4,4-Tetramethylpentane | β57.8 | β241.8 |
C9H20 | 2,2,3,3-Tetramethylpentane | β56.7 | β237.2 |
C9H20 | 2,2,3,4-Tetramethylpentane | β56.6 | β236.8 |
C9H20 | 2,3,3,4-Tetramethylpentane | β56.4 | β236.0 |
C9H20 | 3,3-Diethylpentane | β55.7 | β233.0 |
Other organic compounds
Species | Phase | Chemical formula | ΞfH⦡ /(kJ/mol) |
---|---|---|---|
Acetone | Liquid | C3H6O | β248.4 |
Benzene | Liquid | C6H6 | 48.95 |
Benzoic acid | Solid | C7H6O2 | β385.2 |
Carbon tetrachloride | Liquid | CCl4 | β135.4 |
Carbon tetrachloride | Gas | CCl4 | β95.98 |
Ethanol | Liquid | C2H5OH | β277.0 |
Ethanol | Gas | C2H5OH | β235.3 |
Glucose | Solid | C6H12O6 | β1271 |
Isopropanol | Gas | C3H7OH | β318.1 |
Methanol (methyl alcohol) | Liquid | CH3OH | β238.4 |
Methanol (methyl alcohol) | Gas | CH3OH | β201.0 |
Methyl linoleate (Biodiesel) | Gas | C19H34O2 | β356.3 |
Sucrose | Solid | C12H22O11 | β2226.1 |
Trichloromethane (Chloroform) | Liquid | CHCl3 | β134.47 |
Trichloromethane (Chloroform) | Gas | CHCl3 | β103.18 |
Vinyl chloride | Solid | C2H3Cl | β94.12 |
See also
References
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "standard pressure". doi:10.1351/goldbook.S05921
- ^ Oxtoby, David W; Pat Gillis, H; Campion, Alan (2011). Principles of Modern Chemistry. Cengage Learning. p. 547. ISBN 978-0-8400-4931-5.
- ^ Moore, Stanitski, and Jurs. Chemistry: The Molecular Science. 3rd edition. 2008. ISBN 0-495-10521-X. pages 320β321.
- ^ "Enthalpies of Reaction". www.science.uwaterloo.ca. Archived from the original on 25 October 2017. Retrieved 2 May 2018.
- ^ a b Housecroft, C. E.; Sharpe, A. G. (2004). Inorganic Chemistry (2nd ed.). Prentice Hall. p. 392. ISBN 978-0-13-039913-7.
- ^ Green, D.W., ed. (2007). Perry's Chemical Engineers' Handbook (8th ed.). Mcgraw-Hill. pp. 2β191. ISBN 9780071422949.
- ^ Kleykamp, H. (1998). "Gibbs Energy of Formation of SiC: A contribution to the Thermodynamic Stability of the Modifications". Berichte der Bunsengesellschaft fΓΌr physikalische Chemie. 102 (9): 1231β1234. doi:10.1002/bbpc.19981020928.
- ^ "Silicon Carbide, Alpha (SiC)". March 1967. Retrieved 5 February 2019.
- Zumdahl, Steven (2009). Chemical Principles (6th ed.). Boston. New York: Houghton Mifflin. pp. 384β387. ISBN 978-0-547-19626-8.
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