Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Dioxosilane

Formula: SiO2 (cr,l)
CAS RN: 7631-86-9
ATcT ID: 7631-86-9*500
SMILES: O=[Si]=O
InChI: InChI=1S/O2Si/c1-3-2
InChIKey: VYPSYNLAJGMNEJ-UHFFFAOYSA-N
Hills Formula: O2Si1

2D Image:

O=[Si]=O
Aliases: SiO2; Dioxosilane; Silicon dioxide; Quartz; alpha-Quartz; beta-Quartz; Cristobalite; Tridymite; Aventurine; Silica; Silicon oxide; Silicon (IV) oxide; 14808-60-7; 14464-46-1; 99493-55-7; 15468-32-3; 60676-86-0
Relative Molecular Mass: 60.08430 ± 0.00067

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
-906.77-911.75± 0.63kJ/mol

Top contributors to the provenance of ΔfH° of SiO2 (cr,l)

The 14 contributors listed below account for 90.0% of the provenance of ΔfH° of SiO2 (cr,l).

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution
(%)
TN
ID
Reaction Measured Quantity Reference
21.28538.1 Si (cr,l) + 2 F2 (g) → SiF4 (g) ΔrH°(298.15 K) = -385.98 ± 0.19 kcal/molWise 1963, Wise 1963, Wise 1962
18.3546.1 SiF4 (g) + 2 H2O (cr,l) → Si (cr,l) O2 (g) + 4 HF (aq, 5 H2O) ΔrH°(298.15 K) = 899.77 ± 1.20 kJ/molPaulechka 2020, Vorobev 1960, Hummel 1959, Johnson 1987, Good 1964, Good 1964, Johnson 1973
13.58499.1 Si (cr,l) O2 (g) → SiO2 (cr,l) ΔrH°(298.15 K) = -217.58 ± 0.35 (×1.164) kcal/molGood 1964, Good 1964, Good 1962, King 1951
9.2545.1 SiF4 (g) + 2 H2O (cr,l) → SiO2 (cr, quartz) + 4 HF (aq, 5 H2O) ΔrH°(298.15 K) = -11.11 ± 0.37 kJ/molPaulechka 2020, Vorobev 1960, Hummel 1959, Johnson 1987, Good 1964, Good 1964, Kilday 1973, Kilday 1973, Johnson 1973
5.88540.1 SiO2 (vitr) + 2 F2 (g) → SiF4 (g) O2 (g) ΔrH°(298.15 K) = -170.04 ± 0.25 kcal/molWise 1963, Wise 1963
5.88538.3 Si (cr,l) + 2 F2 (g) → SiF4 (g) ΔrH°(298.15 K) = -1615.78 ± 0.46 (×3.292) kJ/molJohnson 1986, Johnson 1986
3.3544.2 H2O (cr,l) F2 (g) → 2 HF (aq, 5 H2O) + 1/2 O2 (g) ΔrH°(298.15 K) = -356.66 ± 0.40 kJ/molPaulechka 2020, Johnson 1987, Vorobev 1960, Hummel 1959, Johnson 1973
3.08539.1 SiO2 (cr,l) + 2 F2 (g) → SiF4 (g) O2 (g) ΔrH°(298.15 K) = -168.26 ± 0.28 (×1.269) kcal/molWise 1963, Wise 1963
2.18481.2 Si (cr,l) → Si (g) ΔrG°(1525 K) = 231.1 ± 2.0 kJ/molBatdorf 1959, 3rd Law
1.9545.2 SiF4 (g) + 2 H2O (cr,l) → SiO2 (cr, quartz) + 4 HF (aq, 5 H2O) ΔrH°(298.15 K) = -11.95 ± 0.25 (×3.221) kJ/molPaulechka 2020, Vorobev 1960, Hummel 1959, Johnson 1987, Good 1964, Good 1964, Johnson 1982, Johnson 1973
1.88631.1 SiH3SiH3 (g) → 2 Si (cr,l) + 3 H2 (g) ΔrH°(298.15 K) = -19.1 ± 0.6 (×1.61) kcal/molGunn 1961, est unc
1.78595.1 SiH4 (g) → Si (cr,l) + 2 H2 (g) ΔrH°(298.15 K) = -8.3 ± 0.5 kcal/molGunn 1961, Gurvich TPIS, est unc
0.9486.1 1/2 H2 (g) + 1/2 F2 (g) → HF (l) ΔrH°(298.15 K) = -303.56 ± 0.27 (×1.354) kJ/molSettle 1994, Johnson 1973, note HF
0.88481.3 Si (cr,l) → Si (g) ΔrH°(1932 K) = 393.1 ± 2.5 (×1.297) kJ/molDrowart 1960, 2nd Law, Gurvich TPIS

Top 10 species with enthalpies of formation correlated to the ΔfH° of SiO2 (cr,l)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.


Correlation
Coefficent
(%)
Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
100.0 DioxosilaneSiO2 (cr, quartz)O=[Si]=O-906.77-911.75± 0.63kJ/mol60.08430 ±
0.00067
7631-86-9*505
97.0 DioxosilaneSiO2 (vitr)O=[Si]=O-826.32-902.25± 0.64kJ/mol60.08430 ±
0.00067
7631-86-9*520
92.1 DioxosilaneSiO2 (cr, cristobalite)O=[Si]=O-904.07-908.93± 0.68kJ/mol60.08430 ±
0.00067
7631-86-9*510
71.3 TetrafluorosilaneSiF4 (g)[Si](F)(F)(F)F-1608.76-1614.27± 0.52kJ/mol104.07911 ±
0.00030
7783-61-1*0
58.1 OxosilyleneSiO (g)[Si]=O-98.37-97.22± 0.54kJ/mol44.08490 ±
0.00042
10097-28-6*0
52.6 Silicon atom dication[Si]+2 (g)[Si++]2814.002816.98± 0.56kJ/mol28.08440 ±
0.00030
14175-55-4*0
52.6 Silicon cationSi+ (g)[Si+]1236.861240.99± 0.56kJ/mol28.08495 ±
0.00030
14067-07-3*0
52.6 Silicon anionSi- (g)[Si-]316.28319.26± 0.56kJ/mol28.08605 ±
0.00030
14337-02-1*0
52.6 SiliconSi (g)[Si]450.34454.68± 0.56kJ/mol28.08550 ±
0.00030
7440-21-3*0
52.6 Silicon atom trication[Si]+3 (g)[Si+3]6045.586048.56± 0.56kJ/mol28.08385 ±
0.00030
14175-56-5*0

Most Influential reactions involving SiO2 (cr,l)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence
Coefficient
TN
ID
Reaction Measured Quantity Reference
1.0008500.1 SiO2 (cr, quartz) → SiO2 (cr,l) ΔrH°(0 K) = 0 ± 0 cm-1Gurvich TPIS
0.5118516.6 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1618 K) = 37.94 ± 0.29 kcal/molRamstad 1961, 3rd Law, Gurvich TPIS
0.1718516.8 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1403 K) = 54.5 ± 0.5 kcal/molEmons 1972, 3rd Law
0.1358499.1 Si (cr,l) O2 (g) → SiO2 (cr,l) ΔrH°(298.15 K) = -217.58 ± 0.35 (×1.164) kcal/molGood 1964, Good 1964, Good 1962, King 1951
0.0898539.1 SiO2 (cr,l) + 2 F2 (g) → SiF4 (g) O2 (g) ΔrH°(298.15 K) = -168.26 ± 0.28 (×1.269) kcal/molWise 1963, Wise 1963
0.0198516.7 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrH°(1618 K) = 162.93 ± 1.5 kcal/molRamstad 1961, 2nd Law
0.0158518.3 SiO2 (cr,l) H2 (g) → SiO (g) H2O (g) ΔrH°(1836 K) = 127.10 ± 0.60 (×1.719) kcal/molRamstad 1961, 2nd Law
0.0128516.9 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1435 K) = 210.22 ± 2.0 (×3.83) kJ/molKubaschewski 1974, 3rd Law
0.0088516.1 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1300 K) = 64.9 ± 2.0 (×1.139) kcal/molGeld 1948, Geld 1948a, 3rd Law, Gurvich TPIS
0.0078516.11 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1797 K) = 100.5 ± 10.0 kJ/molTombs 1952, 3rd Law, Gurvich TPIS
0.0078516.10 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrH°(1435 K) = 683.46 ± 10 kJ/molKubaschewski 1974, 2nd Law
0.0058518.2 SiO2 (cr,l) H2 (g) → SiO (g) H2O (g) ΔrG°(1836 K) = 44.30 ± 0.43 (×4.177) kcal/molRamstad 1961, 3rd Law, Gurvich TPIS
0.0048516.5 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1361 K) = 61.1 ± 0.7 (×4.655) kcal/molGunther 1958, 3rd Law, Gurvich TPIS
0.0028518.1 SiO2 (cr,l) H2 (g) → SiO (g) H2O (g) ΔrG°(1623 K) = 228.5 ± 12 kJ/molGrube 1949, 3rd Law, Gurvich TPIS
0.0018506.1 SiO2 (cr,l) → SiO2 (g) ΔrG°(1855 K) = 258.7 ± 12.5 (×3.589) kJ/molZmbov 1973, Gurvich TPIS, 3rd Law
0.0018516.3 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1398 K) = 50.2 ± 0.5 (×9.514) kcal/molSchafer 1950, 3rd Law, Gurvich TPIS
0.0018516.13 SiO2 (cr,l) Si (cr,l) → 2 SiO (g) ΔrG°(1377 K) = 213.1 ± 12 (×2) kJ/molZmbov 1973, 3rd Law, Gurvich TPIS
0.0008514.5 SiO2 (cr,l) → SiO (g) + 1/2 O2 (g) ΔrG°(1956 K) = 322 ± 20 kJ/molShchedrin 1977, 3rd Law, Gurvich TPIS
0.0008514.6 SiO2 (cr,l) → SiO (g) + 1/2 O2 (g) ΔrG°(1682 K) = 354.7 ± 3.0 (×7.025) kJ/molNesmeyanov 1960, 3rd Law, Gurvich TPIS
0.0008514.2 SiO2 (cr,l) → SiO (g) + 1/2 O2 (g) ΔrG°(1878 K) = 72.5 ± 2.5 (×2.327) kcal/molNagai 1973, 3rd Law


References
1   B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner,
Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited.
J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2   B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner,
Active Thermochemical Tables: Thermochemistry for the 21st Century.
J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3   B. Ruscic and D. H. Bross,
Active Thermochemical Tables (ATcT) values based on ver. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   T. L. Nguyen et al, ongoing studies (2024)
5   B. Ruscic,
Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables.
Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
6   B. Ruscic and D. H. Bross,
Thermochemistry
Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula
The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties
The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.0005 kJ/mol.

Website Functionality Credits
The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

Acknowledgement
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.