silicon carbide
- Formula: CSi
- Molecular weight: 40.0962
- CAS Registry Number: 409-21-2
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- Options:
Gas phase thermochemistry data
Go To: Top, Gas phase ion energetics data, Constants of diatomic molecules, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 172.00 | kcal/mol | Review | Chase, 1998 | Data last reviewed in March, 1966 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 50.913 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1966 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
| Temperature (K) | 298. to 1000. | 1000. to 6000. |
|---|---|---|
| A | 14.41726 | 7.974594 |
| B | 1.057348 | 1.060502 |
| C | -14.76929 | -0.206767 |
| D | 9.335899 | 0.013797 |
| E | -0.400571 | 0.734534 |
| F | 166.4214 | 171.4766 |
| G | 66.36472 | 62.75693 |
| H | 172.0000 | 172.0000 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in March, 1966 | Data last reviewed in March, 1966 |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Ionization energy determinations
| IE (eV) | Method | Reference |
|---|---|---|
| 9.0 | EI | Verhaegen, Stafford, et al., 1964 |
| 9.2 ± 0.4 | EI | Drowart, DeMaria, et al., 1958 |
Constants of diatomic molecules
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Klaus P. Huber and Gerhard H. Herzberg
Data collected through August, 1977
| Symbol | Meaning |
|---|---|
| State | electronic state and / or symmetry symbol |
| Te | minimum electronic energy (cm-1) |
| ωe | vibrational constant – first term (cm-1) |
| ωexe | vibrational constant – second term (cm-1) |
| ωeye | vibrational constant – third term (cm-1) |
| Be | rotational constant in equilibrium position (cm-1) |
| αe | rotational constant – first term (cm-1) |
| γe | rotation-vibration interaction constant (cm-1) |
| De | centrifugal distortion constant (cm-1) |
| βe | rotational constant – first term, centrifugal force (cm-1) |
| re | internuclear distance (Å) |
| Trans. | observed transition(s) corresponding to electronic state |
| ν00 | position of 0-0 band (units noted in table) |
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No spectra have been conclusively assigned to SiC. The following constants are from ab initio calculations Lutz and Ryan, 1974: | ||||||||||||
| a 1Σ+ | (6628) | (1018) | (0.695) | (1.70) | ||||||||
| * 3Σ- | (5597) | (606) | (0.556) | (1.90) | ||||||||
| * 3Πi | 0 1 | (983) | (0.606) | (1.82) 1 | ||||||||
Notes
| 1 | Lovas, 1974 assumes a 1Σ ground state and estimates re = 1.65 from an extrapolation to SiC of the shortening of Si-O, Si-N single bonds in the corresponding diatomic molecules. |
| 2 | Thermochemical value (mass-spectrometry) Verhaegen, Stafford, et al., 1964. |
References
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Constants of diatomic molecules, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Verhaegen, Stafford, et al., 1964
Verhaegen, G.; Stafford, F.E.; Drowart, J.,
Mass spectrometric study of the systems boron-carbon and boron-carbon-silicon,
J. Chem. Phys., 1964, 40, 1622. [all data]
Drowart, DeMaria, et al., 1958
Drowart, J.; DeMaria, G.; Inghram, M.G.,
Thermodynamic study of SiC utilizing a mass spectrometer,
J. Chem. Phys., 1958, 29, 1015. [all data]
Lutz and Ryan, 1974
Lutz, B.L.; Ryan, J.A.,
Silicon carbide: its ground state and predicted spectrum,
Astrophys. J., 1974, 194, 753. [all data]
Lovas, 1974
Lovas, F.J.,
Small silicon molecules: possible sources of the unidentified molecular lines U81.5, U86.2, U89.2, and U90.7,
Astrophys. J., 1974, 193, 265. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Constants of diatomic molecules, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.