Standard Enthalpy Of Formation H2o

Change of enthalpy during the formation of a compound from its elements

In chemistry and thermodynamics, the standard enthalpy of formation or standard oestrus of formation of a compound is the change of enthalpy during the germination of one mole of the substance from its constituent elements, with all substances in their standard states. The standard pressure level value p ^⦵ = 10⁵ Pa (= 100 kPa = ane 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 Δ_f H ^⦵ . The superscript Plimsoll on this symbol indicates that the procedure has occurred under standard conditions at the specified temperature (normally 25 °C or 298.15 K). Standard states are as follows:

1. For a gas: the hypothetical state it would accept assuming information technology obeyed the platonic gas equation at a pressure of 1 bar
2. For a gaseous or solid solute nowadays in a diluted ideal solution: the hypothetical land of concentration of the solute of exactly i mole per liter (1 M) at a pressure level of ane bar extrapolated from infinite dilution
3. For a pure substance or a solvent in a condensed land (a liquid or a solid): the standard state is the pure liquid or solid under a pressure level of 1 bar
4. For an element: the form in which the element is most stable under i bar of force per unit area. One exception is phosphorus, for which the most stable form at 1 bar is black phosphorus, just white phosphorus is chosen equally the standard reference country for zero enthalpy of formation.^[ii]

For case, the standard enthalpy of formation of carbon dioxide would be the enthalpy of the post-obit reaction under the to a higher place conditions:

${\displaystyle {\ce {C(s, graphite) + O2(g) -> CO2(g)}}}$

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, ordinarily stated in kilojoule per mole (kJ mol⁻¹), just 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 standard states (oxygen gas, solid carbon in the form of graphite, etc.) take a standard enthalpy of formation of zero, every bit there is no modify involved in their germination.

The germination reaction is a constant force per unit area and abiding temperature procedure. Since the pressure level of the standard germination reaction is fixed at i bar, the standard formation enthalpy or reaction estrus is a function of temperature. For tabulation purposes, standard formation enthalpies are all given at a single temperature: 298 K, represented by the symbol Δ_f H ^⦵
_{298 Thousand} .

Hess's police force [edit]

For many substances, the germination reaction may be considered as the sum of a number of simpler reactions, either existent or fictitious. The enthalpy of reaction can then be analyzed by applying Hess'southward 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 considering enthalpy is a country role, 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: Born–Haber cycle [edit]

Standard enthalpy change of formation in Born–Haber diagram for lithium fluoride. ΔH _latt corresponds to U_Fifty in the text. The downward arrow "electron affinity" shows the negative quantity –EA_F , since EA_F is usually defined as positive.

For ionic compounds, the standard enthalpy of formation is equivalent to the sum of several terms included in the Born–Haber wheel. For case, the formation of lithium fluoride,

${\displaystyle {\ce {Li(s) + one/2F2(g) -> LiF(south)}}}$

may be considered as the sum of several steps, each with its own enthalpy (or energy, approximately):

1. H _sub , the standard enthalpy of atomization (or sublimation) of solid lithium.
2. IE_Li , the kickoff ionization energy of gaseous lithium.
3. B(F–F), the standard enthalpy of atomization (or bond free energy) of fluorine gas.
4. EA_F , the electron affinity of a fluorine atom.
5. U_L , the lattice energy of lithium fluoride.

The sum of all these enthalpies volition requite the standard enthalpy of germination (ΔH _f ) of lithium fluoride:

${\displaystyle \Delta H_{\text{f}}=\Delta H_{\text{sub}}+{\text{IE}}_{\text{Li}}+{\frac {1}{2}}{\text{B(F–F)}}-{\text{EA}}_{\text{F}}+{\text{U}}_{\text{L}}.}$

In practice, the enthalpy of formation of lithium fluoride can be determined experimentally, just the lattice energy cannot be measured directly. The equation is therefore rearranged in order to evaluate the lattice energy:^[three]

${\displaystyle -U_{\text{50}}=\Delta H_{\text{sub}}+{\text{IE}}_{\text{Li}}+{\frac {i}{ii}}{\text{B(F–F)}}-{\text{EA}}_{\text{F}}-\Delta H_{\text{f}}.}$

Organic compounds [edit]

The formation reactions for well-nigh organic compounds are hypothetical. For instance, carbon and hydrogen won't directly react to form methane (CH₄ ), so that the standard enthalpy of germination cannot be measured directly. However the standard enthalpy of combustion is readily measurable using flop calorimetry. The standard enthalpy of formation is and then determined using Hess's law. The combustion of methane:

${\displaystyle {\ce {CH4 + 2 O2 -> CO2 + two H2o}}}$

is equivalent to the sum of the hypothetical decomposition into elements followed by the combustion of the elements to class carbon dioxide (CO_two ) and water (H₂O):

${\displaystyle {\ce {CH4 -> C + 2H2}}}$

${\displaystyle {\ce {C + O2 -> CO2}}}$

${\displaystyle {\ce {2H2 + O2 -> 2H2O}}}$

Applying Hess's law,

${\displaystyle \Delta _{\text{comb}}H^{\ominus }({\text{CH}}_{iv})=[\Delta _{\text{f}}H^{\ominus }({\text{CO}}_{2})+2\Delta _{\text{f}}H^{\ominus }({\text{H}}_{2}{\text{O}})]-\Delta _{\text{f}}H^{\ominus }({\text{CH}}_{4}).}$

Solving for the standard of enthalpy of germination,

${\displaystyle \Delta _{\text{f}}H^{\ominus }({\text{CH}}_{4})=[\Delta _{\text{f}}H^{\ominus }({\text{CO}}_{2})+2\Delta _{\text{f}}H^{\ominus }({\text{H}}_{2}{\text{O}})]-\Delta _{\text{comb}}H^{\ominus }({\text{CH}}_{4}).}$

The value of ${\displaystyle \Delta _{\text{f}}H^{\ominus }({\text{CH}}_{four})}$ is adamant to exist −74.8 kJ/mol. The negative sign shows that the reaction, if it were to proceed, would exist exothermic; that is, methane is enthalpically more stable than hydrogen gas and carbon.

Information technology is possible to predict heats of germination for unproblematic unstrained organic compounds with the heat of germination grouping additivity method.

Apply in calculation for other reactions [edit]

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 germination of all products. The heat of reaction is then minus the sum of the standard enthalpies of germination of the reactants (each being multiplied by its corresponding stoichiometric coefficient, ν) plus the sum of the standard enthalpies of formation of the products (each too multiplied past its respective stoichiometric coefficient), as shown in the equation below:^[iv]

${\displaystyle \Delta _{\text{r}}H^{\ominus }=\sum \nu \Delta _{\text{f}}H^{\ominus }({\text{products}})-\sum \nu \Delta _{\text{f}}H^{\ominus }({\text{reactants}}).}$

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 as well 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 case, for the combustion of methane, ${\displaystyle {\ce {CH4 + 2O2 -> CO2 + 2H2O}}}$ :

${\displaystyle \Delta _{\text{r}}H^{\ominus }=[\Delta _{\text{f}}H^{\ominus }({\text{CO}}_{2})+2\Delta _{\text{f}}H^{\ominus }({\text{H}}_{2}{\text{O}})]-\Delta _{\text{f}}H^{\ominus }({\text{CH}}_{four})+ii\Delta _{\text{f}}H^{\ominus }({\text{O}}_{ii})].}$

However ${\displaystyle {\ce {O2}}}$ is an element in its standard country, so that ${\displaystyle \Delta _{\text{f}}H^{\ominus }({\text{O}}_{ii})=0}$ , and the rut of reaction is simplified to

${\displaystyle \Delta _{\text{r}}H^{\ominus }=[\Delta _{\text{f}}H^{\ominus }({\text{CO}}_{two})+2\Delta _{\text{f}}H^{\ominus }({\text{H}}_{2}{\text{O}})]-\Delta _{\text{f}}H^{\ominus }({\text{CH}}_{4}),}$

which is the equation in the previous section for the enthalpy of combustion ${\displaystyle \Delta _{\text{rummage}}H^{\ominus }}$ .

Key concepts for doing enthalpy calculations [edit]

1. When a reaction is reversed, the magnitude of ΔH stays the same, but the sign changes.
2. When the balanced equation for a reaction is multiplied by an integer, the corresponding value of ΔH must be multiplied by that integer equally well.
3. The change in enthalpy for a reaction can be calculated from the enthalpies of formation of the reactants and the products
4. 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 land generally take not-zippo standard enthalpies of formation.

Examples: standard enthalpies of germination at 25 °C [edit]

Thermochemical properties of selected substances at 298.15 Grand and 1 atm

Inorganic substances [edit]

Species	Stage	Chemic formula	Δf H ⦵ /(kJ/mol)
Aluminium
Aluminium	Solid	Al	0
Aluminium chloride	Solid	AlCl3	−705.63
Aluminium oxide	Solid	AliiO3	−1675.5
Aluminium hydroxide	Solid	Al(OH)3	−1277
Aluminium sulphate	Solid	Al2(SO4)3	−3440
Barium
Barium chloride	Solid	BaCl2	−858.6
Barium carbonate	Solid	BaCO3	−1216
Barium hydroxide	Solid	Ba(OH)2	−944.7
Barium oxide	Solid	BaO	−548.ane
Barium sulfate	Solid	BaSO4	−1473.three
Beryllium
Beryllium	Solid	Exist	0
Beryllium hydroxide	Solid	Be(OH)2	−903
Beryllium oxide	Solid	BeO	−609.iv
Boron
Boron trichloride	Solid	BCl3	−402.96
Bromine
Bromine	Liquid	Brii	0
Bromide ion	Aqueous	Br−	−121
Bromine	Gas	Br	111.884
Bromine	Gas	Br2	thirty.91
Bromine trifluoride	Gas	BrF3	−255.60
Hydrogen bromide	Gas	HBr	−36.29
Cadmium
Cadmium	Solid	Cd	0
Cadmium oxide	Solid	CdO	−258
Cadmium hydroxide	Solid	Cd(OH)2	−561
Cadmium sulfide	Solid	CdS	−162
Cadmium sulfate	Solid	CdSOiv	−935
Caesium
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	−443.04
Calcium
Calcium	Solid	Ca	0
Calcium	Gas	Ca	178.2
Calcium(II) ion	Gas	Caii+	1925.90
Calcium(2) ion	Aqueous	Ca2+	−542.7
Calcium carbide	Solid	CaC2	−59.eight
Calcium carbonate (Calcite)	Solid	CaCO3	−1206.9
Calcium chloride	Solid	CaCl2	−795.8
Calcium chloride	Aqueous	CaCl2	−877.3
Calcium phosphate	Solid	Cathree(PO4)ii	−4132
Calcium fluoride	Solid	CaF2	−1219.6
Calcium hydride	Solid	CaH2	−186.2
Calcium hydroxide	Solid	Ca(OH)2	−986.09
Calcium hydroxide	Aqueous	Ca(OH)2	−1002.82
Calcium oxide	Solid	CaO	−635.09
Calcium sulfate	Solid	CaSOfour	−1434.52
Calcium sulfide	Solid	CaS	−482.4
Wollastonite	Solid	CaSiO3	−1630
Carbon
Carbon (Graphite)	Solid	C	0
Carbon (Diamond)	Solid	C	i.ix
Carbon	Gas	C	716.67
Carbon dioxide	Gas	COii	−393.509
Carbon disulfide	Liquid	CSii	89.41
Carbon disulfide	Gas	CS2	116.seven
Carbon monoxide	Gas	CO	−110.525
Carbonyl chloride (Phosgene)	Gas	COCl2	−218.8
Carbon dioxide (united nations–ionized)	Aqueous	CO2(aq)	−419.26
Bicarbonate ion	Aqueous	HCO3 –	−689.93
Carbonate ion	Aqueous	COiii ii–	−675.23
Chlorine
Monatomic chlorine	Gas	Cl	121.vii
Chloride ion	Aqueous	Cl−	−167.2
Chlorine	Gas	Cl2	0
Chromium
Chromium	Solid	Cr	0
Copper
Copper	Solid	Cu	0
Copper(2) oxide	Solid	CuO	−155.two
Copper(Two) sulfate	Aqueous	CuSOiv	−769.98
Fluorine
Fluorine	Gas	F2	0
Hydrogen
Monatomic hydrogen	Gas	H	218
Hydrogen	Gas	Htwo	0
Water	Gas	H2O	−241.818
Water	Liquid	H2O	−285.viii
Hydrogen ion	Aqueous	H+	0
Hydroxide ion	Aqueous	OH−	−230
Hydrogen peroxide	Liquid	H2Oii	−187.8
Phosphoric acid	Liquid	H3POfour	−1288
Hydrogen cyanide	Gas	HCN	130.5
Hydrogen bromide	Liquid	HBr	−36.three
Hydrogen chloride	Gas	HCl	−92.xxx
Hydrogen chloride	Aqueous	HCl	−167.2
Hydrogen fluoride	Gas	HF	−273.3
Hydrogen iodide	Gas	Howdy	26.5
Iodine
Iodine	Solid	I2	0
Iodine	Gas	I2	62.438
Iodine	Aqueous	I2	23
Iodide ion	Aqueous	I−	−55
Iron
Atomic number 26	Solid	Fe	0
Atomic number 26 carbide (Cementite)	Solid	Atomic number 263C	5.4
Atomic number 26(II) carbonate (Siderite)	Solid	FeCO3	−750.6
Iron(Iii) chloride	Solid	FeCl3	−399.iv
Atomic number 26(2) oxide (Wüstite)	Solid	FeO	−272
Iron(2,III) oxide (Magnetite)	Solid	Iron3O4	−1118.4
Iron(III) oxide (Hematite)	Solid	Fe2O3	−824.2
Atomic number 26(Ii) sulfate	Solid	FeSO4	−929
Iron(III) sulfate	Solid	Fe2(SO4)three	−2583
Iron(2) sulfide	Solid	FeS	−102
Pyrite	Solid	FeStwo	−178
Atomic number 82
Lead	Solid	Lead	0
Lead dioxide	Solid	PbO2	−277
Lead sulfide	Solid	PbS	−100
Lead sulfate	Solid	PbSOiv	−920
Lead(II) nitrate	Solid	Lead(NOiii)two	−452
Lead(II) sulfate	Solid	PbSOfour	−920
Lithium
Lithium fluoride	Solid	LiF	−616.93
Magnesium
Magnesium	Solid	Mg	0
Magnesium ion	Aqueous	Mg2+	−466.85
Magnesium carbonate	Solid	MgCOthree	−1095.797
Magnesium chloride	Solid	MgCl2	−641.eight
Magnesium hydroxide	Solid	Mg(OH)two	−924.54
Magnesium hydroxide	Aqueous	Mg(OH)two	−926.8
Magnesium oxide	Solid	MgO	−601.6
Magnesium sulfate	Solid	MgSOfour	−1278.ii
Manganese
Manganese	Solid	Mn	0
Manganese(II) oxide	Solid	MnO	−384.9
Manganese(Four) oxide	Solid	MnO2	−519.vii
Manganese(III) oxide	Solid	MniiO3	−971
Manganese(II,Iii) oxide	Solid	Mn3O4	−1387
Permanganate	Aqueous	MnO − iv	−543
Mercury
Mercury(II) oxide (red)	Solid	HgO	−90.83
Mercury sulfide (scarlet, cinnabar)	Solid	HgS	−58.two
Nitrogen
Nitrogen	Gas	Ntwo	0
Ammonia (ammonium hydroxide)	Aqueous	NHiii (NH4OH)	−lxxx.eight
Ammonia	Gas	NH3	−46.i
Ammonium nitrate	Solid	NH4NO3	−365.6
Ammonium chloride	Solid	NHivCl	−314.55
Nitrogen dioxide	Gas	NO2	33.2
Hydrazine	Gas	N2H4	95.4
Hydrazine	Liquid	Due north2Hfour	50.six
Nitrous oxide	Gas	N2O	82.05
Nitric oxide	Gas	NO	xc.29
Dinitrogen tetroxide	Gas	Due north2O4	9.16
Dinitrogen pentoxide	Solid	North2Ov	−43.1
Dinitrogen pentoxide	Gas	N2O5	11.3
Nitric acrid	Aqueous	HNO3	−207
Oxygen
Monatomic oxygen	Gas	O	249
Oxygen	Gas	O2	0
Ozone	Gas	O3	143
Phosphorus
White phosphorus	Solid	P4	0
Cerise phosphorus	Solid	P	−17.4[five]
Black phosphorus	Solid	P	−39.3[five]
Phosphorus trichloride	Liquid	PClthree	−319.vii
Phosphorus trichloride	Gas	PCl3	−278
Phosphorus pentachloride	Solid	PClfive	−440
Phosphorus pentachloride	Gas	PClv	−321
Phosphorus pentoxide	Solid	PtwoOv	−1505.5[half-dozen]
Potassium
Potassium bromide	Solid	KBr	−392.ii
Potassium carbonate	Solid	Thou2CO3	−1150
Potassium chlorate	Solid	KClO3	−391.iv
Potassium chloride	Solid	KCl	−436.68
Potassium fluoride	Solid	KF	−562.6
Potassium oxide	Solid	K2O	−363
Potassium nitrate	Solid	KNO3	−494.five
Potassium perchlorate	Solid	KClO4	−430.12
Silicon
Silicon	Gas	Si	368.two
Silicon carbide	Solid	SiC	−74.4,[seven] −71.v[eight]
Silicon tetrachloride	Liquid	SiCliv	−640.ane
Silica (Quartz)	Solid	SiO2	−910.86
Silvery
Silverish bromide	Solid	AgBr	−99.5
Argent chloride	Solid	AgCl	−127.01
Silver iodide	Solid	AgI	−62.4
Silver oxide	Solid	Ag2O	−31.1
Silver sulfide	Solid	Ag2South	−31.8
Sodium
Sodium	Solid	Na	0
Sodium	Gas	Na	107.5
Sodium bicarbonate	Solid	NaHCOthree	−950.8
Sodium carbonate	Solid	Na2COthree	−1130.77
Sodium chloride	Aqueous	NaCl	−407.27
Sodium chloride	Solid	NaCl	−411.12
Sodium chloride	Liquid	NaCl	−385.92
Sodium chloride	Gas	NaCl	−181.42
Sodium chlorate	Solid	NaClOiii	−365.4
Sodium fluoride	Solid	NaF	−569.0
Sodium hydroxide	Aqueous	NaOH	−469.15
Sodium hydroxide	Solid	NaOH	−425.93
Sodium hypochlorite	Solid	NaOCl	−347.1
Sodium nitrate	Aqueous	NaNO3	−446.ii
Sodium nitrate	Solid	NaNOthree	−424.viii
Sodium oxide	Solid	Na2O	−414.two
Sulfur
Sulfur (monoclinic)	Solid	S8	0.3
Sulfur (rhombic)	Solid	Southward8	0
Hydrogen sulfide	Gas	HiiSouth	−twenty.63
Sulfur dioxide	Gas	SO2	−296.84
Sulfur trioxide	Gas	SO3	−395.7
Sulfuric acid	Liquid	H2And so4	−814
Tin can
Titanium
Titanium	Gas	Ti	468
Titanium tetrachloride	Gas	TiCl4	−763.two
Titanium tetrachloride	Liquid	TiCliv	−804.2
Titanium dioxide	Solid	TiO2	−944.vii
Zinc
Zinc	Gas	Zn	130.vii
Zinc chloride	Solid	ZnCltwo	−415.1
Zinc oxide	Solid	ZnO	−348.0
Zinc sulfate	Solid	ZnSO4	−980.14

Aliphatic hydrocarbons [edit]

Formula	Name	Δf H ⦵ /(kcal/mol)	Δf H ⦵ /(kJ/mol)
Straight-chain
CH4	Marsh gas	−17.9	−74.9
C2Hvi	Ethane	−twenty.0	−83.7
C2H4	Ethylene	12.5	52.5
CiiHii	Acetylene	54.2	226.viii
CiiiHviii	Propane	−25.0	−104.6
CfourHx	n-Butane	−30.0	−125.five
C5H12	n-Pentane	−35.1	−146.9
CviH14	north-Hexane	−40.0	−167.four
C7Hxvi	northward-Heptane	−44.ix	−187.9
C8Heighteen	north-Octane	−49.8	−208.4
C9H20	n-Nonane	−54.8	−229.3
C10H22	n-Decane	−59.6	−249.four
Cfour Alkane branched isomers
C4H10	Isobutane (methylpropane)	−32.1	−134.3
C5 Paraffin branched isomers
C5H12	Neopentane (dimethylpropane)	−40.1	−167.eight
CfiveH12	Isopentane (methylbutane)	−36.9	−154.4
C6 Paraffin branched isomers
C6Hfourteen	two,2-Dimethylbutane	−44.5	−186.2
C6H14	2,3-Dimethylbutane	−42.five	−177.8
C6Hfourteen	two-Methylpentane (isohexane)	−41.8	−174.9
C6Hxiv	iii-Methylpentane	−41.i	−172.0
C7 Alkane branched isomers
C7H16	2,2-Dimethylpentane	−49.2	−205.9
CsevenH16	2,2,iii-Trimethylbutane	−49.0	−205.0
CsevenH16	three,3-Dimethylpentane	−48.i	−201.3
CviiH16	2,3-Dimethylpentane	−47.three	−197.9
C7H16	two,4-Dimethylpentane	−48.2	−201.seven
C7H16	ii-Methylhexane	−46.v	−194.6
CsevenH16	3-Methylhexane	−45.7	−191.two
C7H16	three-Ethylpentane	−45.3	−189.5
C8 Alkane branched isomers
CeightH18	2,3-Dimethylhexane	−55.ane	−230.v
C8H18	2,two,3,3-Tetramethylbutane	−53.9	−225.five
C8H18	two,2-Dimethylhexane	−53.7	−224.7
C8Hxviii	2,two,4-Trimethylpentane (isooctane)	−53.v	−223.8
CviiiHeighteen	ii,five-Dimethylhexane	−53.two	−222.vi
C8H18	two,two,3-Trimethylpentane	−52.six	−220.one
C8H18	3,3-Dimethylhexane	−52.6	−220.1
C8H18	2,4-Dimethylhexane	−52.four	−219.2
CeightH18	2,three,4-Trimethylpentane	−51.9	−217.1
C8Heighteen	2,3,iii-Trimethylpentane	−51.7	−216.3
C8H18	ii-Methylheptane	−51.5	−215.5
CeightH18	3-Ethyl-3-Methylpentane	−51.4	−215.1
C8H18	iii,4-Dimethylhexane	−l.9	−213.0
C8H18	iii-Ethyl-ii-Methylpentane	−50.4	−210.nine
C8Heighteen	3-Methylheptane	−lx.three	−252.5
C8H18	4-Methylheptane	?	?
C8H18	3-Ethylhexane	?	?
C9 Alkane branched isomers (selected)
C9H20	2,2,iv,4-Tetramethylpentane	−57.8	−241.viii
CixH20	2,ii,three,3-Tetramethylpentane	−56.7	−237.2
C9H20	2,2,iii,iv-Tetramethylpentane	−56.half dozen	−236.eight
C9Htwenty	2,iii,3,four-Tetramethylpentane	−56.four	−236.0
C9Htwenty	3,3-Diethylpentane	−55.vii	−233.0

Other organic compounds [edit]

Species	Phase	Chemical formula	Δf H ⦵ /(kJ/mol)
Acetone	Liquid	C3H6O	−248.4
Benzene	Liquid	C6Hhalf dozen	48.95
Benzoic acid	Solid	C7HsixO2	−385.2
Carbon tetrachloride	Liquid	CClfour	−135.4
Carbon tetrachloride	Gas	CCl4	−95.98
Ethanol	Liquid	C2H5OH	−277.0
Ethanol	Gas	C2HvOH	−235.3
Glucose	Solid	C6H12O6	−1271
Isopropanol	Gas	C3HviiOH	−318.1
Methanol (methyl alcohol)	Liquid	CHthreeOH	−238.4
Methanol (methyl alcohol)	Gas	CH3OH	−201.0
Methyl linoleate (Biodiesel)	Gas	C19H34O2	−356.iii
Sucrose	Solid	C12H22O11	−2226.1
Trichloromethane (Chloroform)	Liquid	CHCl3	−134.47
Trichloromethane (Chloroform)	Gas	CHCliii	−103.18
Vinyl chloride	Solid	CtwoHthreeCl	−94.12

See likewise [edit]

• Calorimetry
• Enthalpy
• Rut of combustion
• Thermochemistry

References [edit]

1. ^ IUPAC, Compendium of Chemic Terminology, 2d ed. (the "Aureate Book") (1997). Online corrected version: (2006–) "standard pressure". doi:ten.1351/goldbook.S05921
2. ^ Oxtoby, David Due west; Pat Gillis, H; Campion, Alan (2011). Principles of Modern Chemistry. p. 547. ISBN978-0-8400-4931-5.
3. ^ Moore, Stanitski, and Jurs. Chemistry: The Molecular Scientific discipline. 3rd edition. 2008. ISBN 0-495-10521-X. pages 320–321.
4. ^ "Enthalpies of Reaction". www.science.uwaterloo.ca. Archived from the original on 25 October 2017. Retrieved 2 May 2018.
5. ^ ^{a b} Housecroft, C. Due east.; Sharpe, A. K. (2004). Inorganic Chemistry (2nd ed.). Prentice Hall. p. 392. ISBN978-0-thirteen-039913-7.
6. ^ Light-green, D.W., ed. (2007). Perry'south Chemical Engineers' Handbook (8th ed.). Mcgraw-Hill. p. two–191. ISBN9780071422949.
7. ^ Kleykamp, H. (1998). "Gibbs Energy of Formation of SiC: A contribution to the Thermodynamic Stability of the Modifications". Berichte der Bunsengesellschaft für physikalische Chemie. 102 (ix): 1231–1234. doi:x.1002/bbpc.19981020928.
8. ^ "Silicon Carbide, Alpha (SiC)". March 1967. Retrieved 5 February 2019.

• Zumdahl, Steven (2009). Chemical Principles (6th ed.). Boston. New York: Houghton Mifflin. pp. 384–387. ISBN978-0-547-19626-8.

External links [edit]

• NIST Chemistry WebBook

Standard Enthalpy Of Formation H2o,

Source: https://en.wikipedia.org/wiki/Standard_enthalpy_of_formation

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