Static Bomb Combustion Calorimeter Research Articles

An isoperibol micro-bomb calorimeter for measurement of the enthalpy of combustion of organic compounds. Application to the study of succinic acid and acetanilide

A micro static-bomb combustion calorimeter, developed from a 1107 Parr semi-micro bomb, has been provided with a new micro-bomb and calorimetric bucket. In the best conditions of operation, the energy equivalent of this calorimetric arrangement is just ε(calor)=(731.82 ± 0.22) J · K −1, which means an uncertainty of 0.03 per cent for the calibration with benzoic acid NIST 39j. This combustion calorimeter has been used in the measurement of the enthalpy of combustion of the succinic acid and acetanilide, giving −(1489.3 ± 1.6) kJ · mol −1 and −(4222.5 ± 1.1) kJ · mol −1, respectively, for these substances.

Enthalpy of combustion, vapour pressures, and enthalpy of sublimation of 3-nitrophenol

Using a static-bomb combustion calorimeter, the standard (p° = 0.1 MPa) molar enthalpy of combustion at the temperature 298.15 K of 3-nitrophenol was determined: − ΔcH°m(cr)/(kJ·mol−1) = 2870.0±1.5. The vapour pressure of the crystals was measured, as a function of the temperature T, by the Knudsen-effusion technique and the standard molar enthalpy of sublimation at T = 323.13 K was derived by the Clausius-Clapeyron equation: ΔgcrH°m(323.13 K)/(kJ·mol−1) = 98.92±0.58. From this value the standard molar enthalpy of sublimation at T = 298.15 K was calculated as ΔgcrH°m(298.15 K)/(kJ·mol−1) = 100.2±0.6.

A high-precision aneroid static-bomb combustion calorimeter for samples of about 20 mg. The standard enthalpy of formation of bicyclo[3.3.3]undecane

An aneroid static-bomb combustion calorimeter has been built and tested. The calorimeter, intended for the combustion calorimetry of relatively volatile hydrocarbons, has been calibrated by the combustion of thermochemical standard benzoic acid. The standard deviation of the mean in a series of eight experiments was less than 0.02 per cent. The energy of combustion of polythene, used to enclose the samples for combustion, has been determined. The standard enthalpy of combustion of bicyclo[3.3.3]undecane has been measured. The quantity ΔH c o = −(1681.2 5 ± 0.4)kcal th mol −1, yields a standard enthalpy of formation ΔH f o(C 11H 20, c) = −(36.4 6 ± 0.4 2) kcal th mol −1. The corresponding gas-phase enthalpy of formation is ΔH f o(C 11H 20, g) = −(21.2 6 ± 0.4 7) kcal th mol −1.

The enthalpy of formation of diamantane

Diamantane (“congressane”) has been burnt in a static bomb combustion calorimeter. The standard enthalpy of combustion was ΔH° = −(1932.31±0.40) kcal mol−1 which yields a standard enthalpy of formation ΔH°f(C14H20,c) = −(67.55±0.42) kcal mol−1. The molecule would appear to have a similar strain energy to adamantane.

The enthalpy of formation of adamantane

Adamantane has been burnt in a static bomb combustion calorimeter. The standard enthalpy of combustion was ΔHoc = -(1442.01 ± 0.78) kcal mol−1, which yields a standard enthalpy of formation ΔHof(C10H16,c) = -(45.02 ± 0.79) kcal mol−1. The thermodynamic properties of adamantane at 298.15 K have been calculated

The enthalpy of formation of mercury diphenyl and some associated bond energies

Mercury diphenyl has been burnt in a static bomb combustion calorimeter. The standard enthalpy of combustion is Δ H ° o = (−1537.8±1.9) kcal mol −1 , which yields a standard enthalpy of formation Δ H ° f (HgPh 2 ,c) = (67.6±1.9) kcal mol −1 . A self-consistent bond energy scheme has been constructed for organo-mercury compounds and some associated bond dissociation energies have been calculated.