Atomization energies of the gaseous molecules LaC and La sub 2 C by high-temperature equilibrium measurements

Journal Article · Thu Feb 23 00:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100341a077· OSTI ID:5040240

Pelino, M ^[1]; Gingerich, K A ^[2]

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1. Universita di L'Aquila (Italy)
2. Texas A and M Univ., College Station (USA)

The Knudsen effusion mass spectrometric technique has been used to determine the thermodynamic properties of the molecules LaC and La{sub 2}C. The enthalpies of the reactions La(g) + C(graphite) = LaC(g) and 2La(g) + C(graphite) + La{sub 2}C(g) were measured in two runs in the temperature ranges 2286-2609 and 2767-2835 K, respectively, resulting in {Delta}H{sub 0}{degree} (reaction 1) = 253 {plus minus} 18 kJ mol{sup {minus}1} and {Delta}H{sub 0}{degree} (reaction 2) = -234 {plus minus} 25 kJ mol{sup {minus}1}. From these values the atomization energies, {Delta}H{sub a}{degree}{sub 0}, and standard heats of formation, {Delta}H{sub f}{degree}{sub 298.15}, were obtained as 458 {plus minus} 20 and 685 {plus minus} 20 and 685 {plus minus} 20 kJ mol{sup {minus}1} for LaC and 945 {plus minus} 28 and 625 {plus minus} 28 kJ mol{sup {minus}1} for La{sub 2}C.

• OSTI ID: 5040240
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:4; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
LANTHANUM CARBIDES
DISSOCIATION HEAT
ENTHALPY
EXPERIMENTAL DATA
GASES
HIGH TEMPERATURE
MASS SPECTROSCOPY
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
CARBIDES
CARBON COMPOUNDS
DATA
FLUIDS
INFORMATION
LANTHANUM COMPOUNDS
NUMERICAL DATA
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
REACTION HEAT
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties