Chemical thermodynamic properties of 3-methylthiophene from 0 to 1000/sup 0/K

Journal Article · Tue Oct 20 04:00:00 EST 1953 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja01116a052· OSTI ID:7098502

McCullough, J P; Sunner, S; Finke, H L; Hubbard, W N; Gross, M E; Pennington, R E; Messerly, J F; Good, W D; Waddington, G

An experimental study has been made of various thermodynamic properties of 3-methylthiophene in the solid, liquid and vapor states (12 to 473/sup 0/K). The entropy of the liquid at 298.16/sup 0/K, 52.18 +- 0.10 cal. deg./sup -1/ mole/sup -1/, was computed from measured values of the heat capacity of the solid and liquid and the heat of fusion (2518 cal. mole/sup -1/ at the triple point, 204.19 +- 0.05/sup 0/K). Experimental results obtained for the heat capacity of the liquid (C/sub satd/), the heat of vaporization (..delta..H/sub v/), the heat capacity in the ideal gaseous state (C/sup 0//sub p/), and the second virial coefficient (B = (PV - RT)/P) are represented by the empirical equations: (1) C/sub satd/(liq.) = 46.074 - 0.17610T + 6.8006 x 10/sup -4/T/sup 2/ - 6.8021 x 10/sup -7/T/sup 2/, cal. deg./sup -1/ mole/sup -1/ (207 to 337/sup 0/K); (2) ..delta..H/sub v/ = 13,593 - 13.913 T, cal. mole/sup -1/ (329 to 389/sup 0/K); (3) C/sup 0//sub p/ = -1.375 + 9.4508 x 10/sup -2/ T - 4.2587 x 10/sup -5/ T/sup 2/, cal. deg./sup -1/ mole/sup -1/ (375 to 473/sup 0/K); and (4) B = 75 - 94.56 exp (1000/T), cc. mole/sup -1/ (329 to 473/sup 0/K). From determinations of the heat of combustion, the standard heat of formation (..delta..H/sub 1//sup 0/ (liq.)) of 3-methylthiophene from graphite, hydrogen and rhombic sulfur was found to be 10.49 +- 0.20 kcal. mole/sup -1/ at 298.16/sup 0/K. Calorimetric, spectroscopic and molecular structure data were used to compute the functions (F/sup 0/ - H/sub 0//sup 0/)/T, (H/sup 0/ -H/sub 0//sup 0/)/T,H/sup 0/ - H/sub 0//sup 0/, S/sup 0/ and C/sup 0//sub p/ at selected temperatures from 0 to 1000/sup 0/K. The height of the potential barrier to internal rotation (ca. 600 cal. mole/sup -1/) required for these calculations was evaluated from the experimental entropy and vapor heat capacity data. Values of ..delta..H/sub 1//sup 0/, ..delta..F/sub 1//sup 0/, and log/sub 10/K/sub 1/, for the formation of 3-methylthiophene in the ideal gaseous state from graphite, hydrogen and gaseous diatomic sulfur, were computed from the thermodynamic functions and appropriate calorimetric data.

• Research Organization: Bureau of Mines, Bartlesville, OK
• OSTI ID: 7098502
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 75:20; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
COMBUSTION HEAT
ENERGY
ENTHALPY
ENTROPY
FLUIDS
FORMATION HEAT
FUSION HEAT
GASES
HEAT
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
LIQUIDS
LOW TEMPERATURE
MEDIUM TEMPERATURE
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHYSICAL PROPERTIES
REACTION HEAT
SOLIDS
SPECIFIC HEAT
THERMODYNAMIC PROPERTIES
TRANSITION HEAT
ULTRALOW TEMPERATURE
VAPORIZATION HEAT
VAPORS
VERY LOW TEMPERATURE