Sulfuric Acid

Formula: H₂O₄S
Molecular weight: 98.078
IUPAC Standard InChI: InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)
IUPAC Standard InChIKey: QAOWNCQODCNURD-UHFFFAOYSA-N
CAS Registry Number: 7664-93-9
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
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Other names: H2SO4; Dipping acid; Hydrogen sulfate; Oil of vitriol; Sulphuric acid; Acide sulfurique; Acido solforico; BOV; Matting acid; Nordhausen acid; Schwefelsaeureloesungen; Vitriol brown oil; Vitriol, oil of; Zwavelzuuroplossingen; O2S(OH)2; Battery acid; Electrolyte acid; Spirit of alum; Spirit of vitriol; Dihydrogen sulfate; Mattling acid; UN 1830 (Salt/Mix); UN 1832 (Salt/Mix); UN 2796 (Salt/Mix)
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Information on this page:
Other data available:
- Henry's Law data
- Mass spectrum (electron ionization)
Data at other public NIST sites:
- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

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Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-175.70	kcal/mol	Review	Chase, 1998	Data last reviewed in September, 1977
Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	71.410	cal/mol*K	Review	Chase, 1998	Data last reviewed in September, 1977

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
C_p = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.

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Temperature (K)	298. to 1200.	1200. to 6000.
A	11.30240	33.27651
B	45.49030	2.273821
C	-35.40390	-0.429153
D	10.48430	0.028219
E	-0.176868	-3.732042
F	-181.3940	-194.3350
G	72.01150	99.47070
H	-175.7000	-175.7000
Reference	Chase, 1998	Chase, 1998
Comment	Data last reviewed in September, 1977	Data last reviewed in September, 1977

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Ion clustering data, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
MS - José A. Martinho Simões
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

HO₄S^- + = Sulfuric Acid

By formula: HO₄S^- + H⁺ = H₂O₄S

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	309.6 ± 5.4	kcal/mol	D-EA	Wang, Nicholas, et al., 2000	gas phase; Lit BDE seems too weak. This plus Viggiano, Henchman, et al., 1992 gives BDE=106; B
Δ_rH°	309.6 ± 2.6	kcal/mol	G+TS	Viggiano, Henchman, et al., 1992	gas phase; B
Δ_rH°	316.80	kcal/mol	Latt	House Jr. and Kemper, 1987	gas phase; From lattice energy of NH4HSO4, with new PA(NH3); B
Δ_rH°	<315.40	kcal/mol	G+TS	Vigiano, Perry, et al., 1980	gas phase; I^- + H₂SO₄ ->.; B
Δ_rH°	<313.6 ± 2.0	kcal/mol	EIAE	Adams, Smith, et al., 1986	gas phase; From H₂SO₄ (AP 0eV); B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	302.3 ± 5.5	kcal/mol	H-TS	Wang, Nicholas, et al., 2000	gas phase; Lit BDE seems too weak. This plus Viggiano, Henchman, et al., 1992 gives BDE=106; B
Δ_rG°	302.3 ± 2.5	kcal/mol	IMRB	Viggiano, Henchman, et al., 1992	gas phase; B
Δ_rG°	<308.00	kcal/mol	IMRB	Vigiano, Perry, et al., 1980	gas phase; I^- + H₂SO₄ ->.; B
Δ_rG°	<306.2 ± 2.3	kcal/mol	H-TS	Adams, Smith, et al., 1986	gas phase; From H₂SO₄ (AP 0eV); B

C₂H₅NaO (cr) + 0.5( Sulfuric Acid • 1100) (solution) = (solution) + 0.5 (solution)

By formula: C₂H₅NaO (cr) + 0.5(H₂O₄S • 1100H₂O) (solution) = C₂H₆O (solution) + 0.5Na₂O₄S (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-28.30 ± 0.91	kcal/mol	RSC	Blanchard, Joly, et al., 1974	solvent: Sulphuric acid aqueous solution; The reaction enthalpy relies on -2.53 kcal/mol for the enthalpy of solution of EtOH(l) and on 9.97±0.04 for the enthalpy of solution of Na2SO4(cr) Blanchard, Joly, et al., 1974. A value of -117.3 ± 1.4 kcal/mol was derived in Blanchard, Joly, et al., 1974 for the enthalpy of formation. However, this value is affected by a calculation error. Also, the authors have not accounted for the acid dilution (this correction could not be made in the present database, due to lack of information). These problems were also noted in the data compilations Tel'noi and Rabinovich, 1980 and Wagman, Evans W.H., et al., 1982, where the values quoted for the enthalpy of formation, which rely on the experimental data reported in Blanchard, Joly, et al., 1974, are -98.0 ± 1.0 kcal/mol and -98.90 kcal/mol, respectively. See also comments in Liebman, Martinho Simões, et al., 1995; MS

(HO₄S^- • 2 Sulfuric Acid ) + HO₃S = (HO₄S^- • HO₃S • 2)

By formula: (HO₄S^- • 2H₂O₄S) + HO₃S = (HO₄S^- • HO₃S • 2H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.0	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Δ_rH°	18.	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
14.8	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
12.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M

(HO₄S^- • 2 Sulfuric Acid ) + = (HO₄S^- • 3)

By formula: (HO₄S^- • 2H₂O₄S) + H₂O₄S = (HO₄S^- • 3H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.8	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Δ_rH°	19.8	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
14.6	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
14.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • • 3 Sulfuric Acid ) + = (HO₄S^- • 2 • 3)

By formula: (HO₄S^- • H₂O • 3H₂O₄S) + H₂O = (HO₄S^- • 2H₂O • 3H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.0	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
7.2	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(H₂O₄S^- • Sulfuric Acid ) + HO₃S = (H₂O₄S^- • HO₃S • )

By formula: (H₂O₄S^- • H₂O₄S) + HO₃S = (H₂O₄S^- • HO₃S • H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22.1	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
15.9	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 2 Sulfuric Acid ) + = (HO₄S^- • • 2)

By formula: (HO₄S^- • 2H₂O₄S) + HNO₃ = (HO₄S^- • HNO₃ • 2H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.9	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
10.3	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 3 Sulfuric Acid ) + = (HO₄S^- • • 3)

By formula: (HO₄S^- • 3H₂O₄S) + HNO₃ = (HO₄S^- • HNO₃ • 3H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.9	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
11.1	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 2 Sulfuric Acid ) + = (HO₄S^- • • 2)

By formula: (HO₄S^- • 2H₂O₄S) + H₂O = (HO₄S^- • H₂O • 2H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.1	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.3	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 3 Sulfuric Acid ) + = (HO₄S^- • • 3)

By formula: (HO₄S^- • 3H₂O₄S) + H₂O = (HO₄S^- • H₂O • 3H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.8	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
8.0	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 4 Sulfuric Acid ) + = (HO₄S^- • • 4)

By formula: (HO₄S^- • 4H₂O₄S) + H₂O = (HO₄S^- • H₂O • 4H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.9	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
8.1	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • Sulfuric Acid ) + = (HO₄S^- • 2)

By formula: (HO₄S^- • H₂O₄S) + H₂O₄S = (HO₄S^- • 2H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22.0	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
15.8	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 3 Sulfuric Acid ) + = (HO₄S^- • 4)

By formula: (HO₄S^- • 3H₂O₄S) + H₂O₄S = (HO₄S^- • 4H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.5	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
13.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

(HO₄S^- • 4 Sulfuric Acid ) + = (HO₄S^- • 5)

By formula: (HO₄S^- • 4H₂O₄S) + H₂O₄S = (HO₄S^- • 5H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.9	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
13.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated; M

C₂H₅LiO (cr) + 0.5( Sulfuric Acid • 1100) (solution) = 0.5Li₂O₄S (solution) + (solution)

By formula: C₂H₅LiO (cr) + 0.5(H₂O₄S • 1100H₂O) (solution) = 0.5Li₂O₄S (solution) + C₂H₆O (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-27.15 ± 0.31	kcal/mol	RSC	Blanchard, Joly, et al., 1974	solvent: Sulphuric acid aqueous solution; The reaction enthalpy relies on -2.53 kcal/mol for the enthalpy of solution of EtOH(l) and on -17.5±0.3 for the enthalpy of solution of Li2SO4(cr) Blanchard, Joly, et al., 1974.; MS

C₂H₅KO (cr) + 0.5( Sulfuric Acid • 1100) (solution) = (solution) + 0.5K₂O₄S (solution)

By formula: C₂H₅KO (cr) + 0.5(H₂O₄S • 1100H₂O) (solution) = C₂H₆O (solution) + 0.5K₂O₄S (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-31.62 ± 0.69	kcal/mol	RSC	Blanchard, Joly, et al., 1974	solvent: Sulphuric acid aqueous solution; The reaction enthalpy relies on -2.53 kcal/mol for the enthalpy of solution of EtOH(l) and on 35.1±0.1 for the enthalpy of solution of K2SO4(cr) Blanchard, Joly, et al., 1974.; MS

(l) + ( Sulfuric Acid • 100) (solution) = 2 (g) + ( • 100) (solution)

By formula: C₂H₆Zn (l) + (H₂O₄S • 100H₂O) (solution) = 2CH₄ (g) + (O₄SZn • 100H₂O) (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-81.7 ± 0.2	kcal/mol	RSC	Carson, Hartley, et al., 1949	Please also see Pedley and Rylance, 1977 and Cox and Pilcher, 1970.; MS

(l) + ( Sulfuric Acid • 100) (solution) = 2 (g) + ( • 100) (solution)

By formula: C₄H₁₀Zn (l) + (H₂O₄S • 100H₂O) (solution) = 2C₂H₆ (g) + (O₄SZn • 100H₂O) (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-84.7 ± 1.0	kcal/mol	RSC	Carson, Hartley, et al., 1949	Please also see Pedley and Rylance, 1977 and Cox and Pilcher, 1970.; MS

+ Sulfuric Acid = C₁₂H₂₆O₃S +

By formula: C₁₂H₂₆ + H₂O₄S = C₁₂H₂₆O₃S + H₂O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	69.3 ± 4.0	kcal/mol	Cm	Roth and Rist-Schumacher, 1944	liquid phase; ALS

+ Sulfuric Acid =

By formula: C₃H₆ + H₂O₄S = isopropyl hydrogen sulphate

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-9.2 ± 0.2	kcal/mol	Eqk	Entelis, Korovina, et al., 1960	liquid phase; ALS

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Ion clustering data, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LL - Sharon G. Lias and Joel F. Liebman

Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	167.2	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	159.4	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_{(+) ion}	119. ± 5.	kcal/mol	N/A	N/A

Gas basicity at 298K

Gas basicity (review) (kcal/mol)	Reference	Comment
163. ± 1.	Do, Klein, et al., 1998	T = T(eff) = 800 - 1250K; H2S; H2CO. ΔGB values from kinetic bracketing were extrapolated to 298 K. ΔSp from ab initio rot. and vib. constants; MM
≥163.	Do, Klein, et al., 1998	MM

Protonation entropy at 298K

Protonation entropy (cal/mol*K)	Reference	Comment
1.2	Do, Klein, et al., 1998	T = T(eff) = 800 - 1250K; H2S; H2CO. ΔGB values from kinetic bracketing were extrapolated to 298 K. ΔSp from ab initio rot. and vib. constants; MM

Ionization energy determinations

IE (eV)	Method	Reference	Comment
12.40 ± 0.05	EI	Snow and Thomas, 1990	LL

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
HSO₃⁺	13.9 ± 0.1	HO	EI	Snow and Thomas, 1990	LL
H₂O⁺	13.2 ± 0.2	SO₃	EI	Snow and Thomas, 1990	LL
SO₂⁺	15.97 ± 0.15	H₂O₂	EI	Snow and Thomas, 1990	LL
SO₃⁺	13.8 ± 0.2	H₂O	EI	Snow and Thomas, 1990	LL

De-protonation reactions

HO₄S^- + = Sulfuric Acid

By formula: HO₄S^- + H⁺ = H₂O₄S

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	309.6 ± 5.4	kcal/mol	D-EA	Wang, Nicholas, et al., 2000	gas phase; Lit BDE seems too weak. This plus Viggiano, Henchman, et al., 1992 gives BDE=106; B
Δ_rH°	309.6 ± 2.6	kcal/mol	G+TS	Viggiano, Henchman, et al., 1992	gas phase; B
Δ_rH°	316.80	kcal/mol	Latt	House Jr. and Kemper, 1987	gas phase; From lattice energy of NH4HSO4, with new PA(NH3); B
Δ_rH°	<315.40	kcal/mol	G+TS	Vigiano, Perry, et al., 1980	gas phase; I^- + H₂SO₄ ->.; B
Δ_rH°	<313.6 ± 2.0	kcal/mol	EIAE	Adams, Smith, et al., 1986	gas phase; From H₂SO₄ (AP 0eV); B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	302.3 ± 5.5	kcal/mol	H-TS	Wang, Nicholas, et al., 2000	gas phase; Lit BDE seems too weak. This plus Viggiano, Henchman, et al., 1992 gives BDE=106; B
Δ_rG°	302.3 ± 2.5	kcal/mol	IMRB	Viggiano, Henchman, et al., 1992	gas phase; B
Δ_rG°	<308.00	kcal/mol	IMRB	Vigiano, Perry, et al., 1980	gas phase; I^- + H₂SO₄ ->.; B
Δ_rG°	<306.2 ± 2.3	kcal/mol	H-TS	Adams, Smith, et al., 1986	gas phase; From H₂SO₄ (AP 0eV); B

Ion clustering data

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Data compiled by: Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

(HO₄S^- • Sulfuric Acid ) + = (HO₄S^- • 2)

By formula: (HO₄S^- • H₂O₄S) + H₂O₄S = (HO₄S^- • 2H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22.0	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
15.8	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated

(HO₄S^- • 2 Sulfuric Acid ) + = (HO₄S^- • 3)

By formula: (HO₄S^- • 2H₂O₄S) + H₂O₄S = (HO₄S^- • 3H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.8	kcal/mol	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated
Δ_rH°	19.8	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
14.6	250.	ATM	Arnold and Qiu, 1984	gas phase; Entropy change calculated or estimated
14.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

(HO₄S^- • 3 Sulfuric Acid ) + = (HO₄S^- • 4)

By formula: (HO₄S^- • 3H₂O₄S) + H₂O₄S = (HO₄S^- • 4H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.5	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
13.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

(HO₄S^- • 4 Sulfuric Acid ) + = (HO₄S^- • 5)

By formula: (HO₄S^- • 4H₂O₄S) + H₂O₄S = (HO₄S^- • 5H₂O₄S)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.9	kcal/mol	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
13.	233.	ATM	Arnold, Viggiano, et al., 1982	gas phase; Entropy change calculated or estimated

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Notes

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Wang, Nicholas, et al., 2000
Wang, X.B.; Nicholas, J.B.; Wang, L.S., Photoelectron spectroscopy and theoretical calculations of SO4- and HSO4-: Confirmation of high electron affinities of SO4 and HSO4, J. Phys. Chem. A, 2000, 104, 3, 504-508, https://doi.org/10.1021/jp992726r . [all data]

Viggiano, Henchman, et al., 1992
Viggiano, A.A.; Henchman, M.J.; Dale, F.; Deakyne, C.A.; Paulson, J.F., Gas-Phase Reactions of Weak Bronsted Bases I-, PO3-, HSO4-, FSO3-, and CF3SO3- with Strong Bronsted Acids H2SO4, FSO3H, and CF3SO3H - A Quantitative Study, J. Am. Chem. Soc., 1992, 114, 11, 4299, https://doi.org/10.1021/ja00037a039 . [all data]

House Jr. and Kemper, 1987
House Jr.; Kemper, K.A., Proton Affinities of Sulfate and Bisulfate Ions, J. Thermal Anal., 1987, 32, 6, 1855, https://doi.org/10.1007/BF01913977 . [all data]

Vigiano, Perry, et al., 1980
Vigiano, A.A.; Perry, R.A.; Albritton, D.L.; Ferguson, E.E.; Fehsenfeld, F.C., The role of H₂SO₄ in stratospheric negative ion chemistry, J. Geophys. Res., 1980, 85, 4551. [all data]

Adams, Smith, et al., 1986
Adams, N.G.; Smith, D.; Viggiano, A.A.; Paulson, J.F.; Henchman, M.J., Dissociative attachment reactions of electron with strong acid molecules, J. Chem. Phys., 1986, 84, 6728. [all data]

Blanchard, Joly, et al., 1974
Blanchard, J.M.; Joly, R.D.; Lettoffe, J.M.; Perachon, G.; Thourey, J., J. Chim. Phys. Phys.-Chim. Biol., 1974, 71, 472. [all data]

Tel'noi and Rabinovich, 1980
Tel'noi, V.I.; Rabinovich, I.B., Russ. Chem. Rev., 1980, 49, 603. [all data]

Wagman, Evans W.H., et al., 1982
Wagman, D.D.; Evans W.H.; Parker, V.B.; Schumm, R.H.; Halow, I.; Bailey, S.M.; Churney, K.L.; Nuttall, R.L., The NBS Tables of Chemical Thermodynamic Properties; J. Phys. Chem. Ref. Data, 1982, 11, Suppl. 2. [all data]

Liebman, Martinho Simões, et al., 1995
Liebman, J.F.; Martinho Simões, J.A.; Slayden, S.W., In Lithium Chemistry: A Theoretical and Experimental Overview Wiley: New York, Sapse, A.-M.; Schleyer, P. von Ragué, ed(s)., 1995. [all data]

Arnold and Qiu, 1984
Arnold, F.; Qiu, S., Upper Stratosphere Negative Ion Composition Measurements and Infrared Trace Gas Abundances, Planet. Space Sci., 1984, 32, 2, 169, https://doi.org/10.1016/0032-0633(84)90151-X . [all data]

Arnold, Viggiano, et al., 1982
Arnold, F.; Viggiano, A.A.; Schlager, H., Implications for Trace Gases and Aerosols of Large Negative Ions Clusters in the Stratosphere, Nature, 1982, 297, 5865, 371, https://doi.org/10.1038/297371a0 . [all data]

Carson, Hartley, et al., 1949
Carson, A.S.; Hartley, K.; Skinner, H.A., Thermochemistry of metal alkyls. Part II.?The bond dissociation energies of some Zn?C and Cd?C bonds, and of Et?I., Trans. Faraday Soc., 1949, 45, 1159, https://doi.org/10.1039/tf9494501159 . [all data]

Pedley and Rylance, 1977
Pedley, J.B.; Rylance, J., Computer Analysed Thermochemical Data: Organic and Organometallic Compounds, University of Sussex, Brigton, 1977. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds in Academic Press, New York, 1970. [all data]

Roth and Rist-Schumacher, 1944
Roth, W.A.; Rist-Schumacher, E., Beitrag zur thermochemie der sulfonsauren und saurechlorid, Z. Electrochem., 1944, 50, 7-9. [all data]

Entelis, Korovina, et al., 1960
Entelis, S.G.; Korovina, G.V.; Chirkov, N.M., The thermodynamics of propylene absorption by the H₂SO₄-H₂0 system, Dokl. Akad. Nauk SSSR, 1960, 134, 856-859. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Do, Klein, et al., 1998
Do, K.; Klein, T.P.; Pommering, C.A.; Bachrach, S.M.; Sunderlin, L.S., The gas-phase basicity of sulfuric acid, J. Am. Chem. Soc., 1998, 120, 6093. [all data]

Snow and Thomas, 1990
Snow, K.B.; Thomas, T.F., Mass spectrum, ionization potential, and appearance potentials for fragment ions of sulfuric acid vapor, Int. J. Mass Spectrom. Ion Processes, 1990, 96, 49. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, References

Symbols used in this document:

AE	Appearance energy
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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