# diboron trioxide

**Formula:**B_{2}O_{3}**Molecular weight:**69.620**CAS Registry Number:**1303-86-2**Information on this page:****Other data available:****Data at other public NIST sites:****Options:**

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## Gas phase thermochemistry data

**Go To:** Top, Condensed phase thermochemistry data, 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 |
---|---|---|---|---|---|

_{f}H°_{gas} | -835.96 | kJ/mol | Review | Chase, 1998 | Data last reviewed in June, 1971 |

Quantity | Value | Units | Method | Reference | Comment |

S°_{gas,1 bar} | 283.77 | J/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1971 |

### Gas Phase Heat Capacity (Shomate Equation)

C_{p}° = A + B*t + C*t^{2} + D*t^{3} +
E/t^{2}

H° − H°_{298.15}= A*t + B*t^{2}/2 +
C*t^{3}/3 + D*t^{4}/4 − E/t + F − H

S° = A*ln(t) + B*t + C*t^{2}/2 + D*t^{3}/3 −
E/(2*t^{2}) + G

C_{p} = heat capacity (J/mol*K)

H° = standard enthalpy (kJ/mol)

S° = standard entropy (J/mol*K)

t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K) | 3000. - 6000. |
---|---|

A | 103.9017 |

B | 2.228369 |

C | -0.434734 |

D | 0.029271 |

E | -10.42071 |

F | -891.5351 |

G | 376.0328 |

H | -835.9632 |

Reference | Chase, 1998 |

Comment | Data last reviewed in June, 1971 |

## Condensed phase thermochemistry data

**Go To:** Top, Gas phase thermochemistry data, 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 |
---|---|---|---|---|---|

_{f}H°_{liquid} | -1253.36 | kJ/mol | Review | Chase, 1998 | Data last reviewed in June, 1971 |

Quantity | Value | Units | Method | Reference | Comment |

S°_{liquid,1 bar} | 78.45 | J/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1971 |

Quantity | Value | Units | Method | Reference | Comment |

_{f}H°_{solid} | -1273.5 ± 1.4 | kJ/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |

_{f}H°_{solid} | -1271.94 | kJ/mol | Review | Chase, 1998 | Data last reviewed in June, 1971 |

Quantity | Value | Units | Method | Reference | Comment |

S°_{solid,1 bar} | 53.97 ± 0.30 | J/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |

Quantity | Value | Units | Method | Reference | Comment |

S°_{solid} | 53.95 | J/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1971 |

### Liquid Phase Heat Capacity (Shomate Equation)

C_{p}° = A + B*t + C*t^{2} + D*t^{3} +
E/t^{2}

H° − H°_{298.15}= A*t + B*t^{2}/2 +
C*t^{3}/3 + D*t^{4}/4 − E/t + F − H

S° = A*ln(t) + B*t + C*t^{2}/2 + D*t^{3}/3 −
E/(2*t^{2}) + G

C_{p} = heat capacity (J/mol*K)

H° = standard enthalpy (kJ/mol)

S° = standard entropy (J/mol*K)

t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K) | 723. - 3000. |
---|---|

A | 111.5690 |

B | 23.17410 |

C | -10.32210 |

D | 1.533191 |

E | 3.539531 |

F | -1290.900 |

G | 188.0810 |

H | -1253.360 |

Reference | Chase, 1998 |

Comment | Data last reviewed in June, 1971 |

### Solid Phase Heat Capacity (Shomate Equation)

C_{p}° = A + B*t + C*t^{2} + D*t^{3} +
E/t^{2}

H° − H°_{298.15}= A*t + B*t^{2}/2 +
C*t^{3}/3 + D*t^{4}/4 − E/t + F − H

S° = A*ln(t) + B*t + C*t^{2}/2 + D*t^{3}/3 −
E/(2*t^{2}) + G

C_{p} = heat capacity (J/mol*K)

H° = standard enthalpy (kJ/mol)

S° = standard entropy (J/mol*K)

t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K) | 298. - 723. |
---|---|

A | 5.431501 |

B | 272.5617 |

C | -252.4956 |

D | 97.65540 |

E | -0.377274 |

F | -1284.902 |

G | -12.50564 |

H | -1271.936 |

Reference | Chase, 1998 |

Comment | Data last reviewed in June, 1971 |

## References

**Go To:** Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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]

**Cox, Wagman, et al., 1984**

Cox, J.D.; Wagman, D.D.; Medvedev, V.A.,
**CODATA Key Values for Thermodynamics**, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

## Notes

**Go To:** Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References

- Symbols used in this document:

S° _{gas,1 bar}Entropy of gas at standard conditions (1 bar) S° _{liquid,1 bar}Entropy of liquid at standard conditions (1 bar) S° _{solid}Entropy of solid at standard conditions S° _{solid,1 bar}Entropy of solid at standard conditions (1 bar) _{f}H°_{gas}Enthalpy of formation of gas at standard conditions _{f}H°_{liquid}Enthalpy of formation of liquid at standard conditions _{f}H°_{solid}Enthalpy of formation of solid at standard conditions - Data from NIST Standard Reference Database 69:
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