| dc.contributor.author | Mousavipour, Seyed Hosein. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:28Z | |
| dc.date.available | 1996 | |
| dc.date.issued | 1996 | en_US |
| dc.identifier.other | AAINN15857 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55116 | |
| dc.description | The kinetics of two reaction systems have been studied. | en_US |
| dc.description | In the first part, the pyrolysis of acetone in a flow system has been investigated during its induction period. In that study gas chromatography and infra-red spectroscopy were used to identify and measure the products. The Troe method was used to study the fall-off behavior of the rate constant for the decomposition of acetone to CH$\sb3$ and CH$\sb3$CO. The limiting high pressure Arrhenius parameters for the decomposition of acetone, $\log\sb \rm\ (A/s\sp{-1}) = 17.9 \pm 0.8\ and\ E\sb{A} = 353 \pm 14\ kJ\ mol\sp{-1}$, were calculated for the first time in the temperature range 825 to 940 K. A transition state theory model was used to study the transition state properties of the reaction of CH$\sb3$ with (CH$\sb3)\sb2$CO. It has been shown that the Arrhenius plot for this reaction is curved. The effective activation energy, 46 $\pm$ 17 kJ mol$\sp{-1}$, the characteristic tunneling temperature, 375 $\pm$ 17 K, and the average transitional vibrational term value, 279 $\pm$ 8 cm$\sp{-1}$, in the transition state were calculated for this reaction. The limiting high pressure Arrhenius parameters for the decomposition of the acetonyl radical, $\rm CH\sb3COCH\sb2\to CH\sb3 + CH\sb2CO,\ log\sb \ (A/s\sp{-1}) = 15.58 \pm 0.26\ and\ E\sb{A} = 184.1 \pm 4.4\ kJ\ mol\sp{-1}$, were found for the first time. The geometry and frequencies of the acetonyl radical and the activated complex for this reaction were investigated at the HF/6-31G$\sp{**}$ level of theory. This information was used to investigate the fall-off behavior for the rate constant of this reaction using RRKM theory. A value for the rate constant for the cross-combination reaction of methyl and acetonyl radicals of $\rm1.5 \pm 0.3 \times 10\sp \ L\ mol\sp{-1}s\sp{-1}$ has been measured for the first time. A value for the rate constant for the recombination reaction of acetonyl radicals of $3.0\times10\sp9\rm\ L\ mol\sp{-1}s\sp{-1}$ has been determined for the first time in this temperature range. | en_US |
| dc.description | The second part of this thesis reports a study of the reaction of hydrogen atoms with ethane at 295 to 516 K and 4.1 to 8.6 Torr in a flow system. ESR and gas chromatography were used to measure the concentrations of H atoms and of the products, respectively. Computer simulation was performed to determine the main reactions and also to optimize the rate constants for the reaction of hydrogen atoms with ethyl radicals to produce methyl radicals and ethylene. The number of hydrogen atoms removed per ethane molecule reacted was calculated to be 4.3 $\pm$ 0.4 at room temperature and to approach 3.1 at 516 K. The Arrhenius parameters for the reaction of hydrogen atoms with ethane, $\rm log\sb \ (A/L\ mol\sp{-1}s\sp{-1}) = 10.38 \pm 0.09\ and\ E\sb{A} = 33.4 \pm 0.7\ kJ\ mol\sp{-1}$ were calculated. The branching ratio for the reactions of hydrogen atoms with ethyl radicals to produce ethylene or methyl radicals was determined to be 0.18 $\pm$ 0.05. Also the ratio of the rate constant for the reaction of hydrogen atoms with ethyl radicals to produce methyl radicals, k$\sb{2.8}$, to the rate constant for the reaction of hydrogen atoms with methyl radicals to produce methane, k$\sb{2.10}$, was found to be ($2.9\pm0.4)\times10\sp{-4}\rm\ mol\ L\sp{-1}$. Using this ratio and a value from the literature for k$\sb{2.10}$, a value of $1.3\times10\sp \rm\ L\ mol\sp{-1}s\sp{-1}$ was found for k$\sb{2.8}$. A value of ($3\pm1)\times10\sp9\rm\ L\ mol\sp{-1}s\sp{-1}$ was found for the rate constant for the reaction of hydrogen atoms with ethyl radicals to produce ethylene. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1996. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Physical. | en_US |
| dc.title | Formation and reactions of radicals during pyrolysis of acetone and reaction of hydrogen atoms with ethane. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
