Essay About Kinetics Of Aromatic Bromination  Name And Mins0.343

Kinetics of Aromatic Bromination
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Chemistry 232     Fall 2015 and Spring 2016 Kinetics of Aromatic Bromination  Name: _____________________________________________ Date: ___________________________ Abstract In this experiment, the kinetics of aromatic bromination were analysed to determine the reactivity different substituents have on aromatic rings. The greatest change of absorbance was found to be benzene, with a change in absorbency of 0.316. Chlorobenzene had the least change in absorbency, which was 0.186. Phenol was found to be the fastest reacting aromatic compound from the experiment. The activation energy (∆G‡) for the bromination of diphenyl ether was 38195.3. General Equation of Bromination       Procedure Reference  Marrs, P. Organic Chemistry Laboratory Manual. pp. 41-52. (University of Victoria, BC). Fall 2015.  Reagents Compound MW Physical and Safety Data  Bromine, Br2 159.82Volatile, highly toxic, oxidizer and corrosive. Bp:58ºC, d: 3.1g/mL Acetic acid, C2H4O2 60.05 Bp:118ºC, d: 1.05g/mL. Irritant, corrosive,  Qualitative Rates of Bromination; Deactivated Aromatic Compounds Benzene Nitrobenzene Chlorobenzene Time A Time A Time A  40 mins0.343  40 mins 0.282 40 mins0.21680 mins  0.09880 mins   0.148 80 mins0.112 120 mins  0.027120 mins  0.067 120 mins0.030  The above results were recorded at ~75°C.  Qualitative Rates of Bromination; Activated Aromatic Compounds Time taken until disappearance of bromine colour Temperature Phenol Diphenyl  Ether p-Bromo-phenol Acetanilide Anisole 0 °C 4.20sNo change 11.90s 7.28s16.83sRoom temp. 4.00s No change 4.10s2.88s 9.96s 50 °C -No change –2.90s Quantitative Rates of Bromination: Diphenyl ether Reaction at  0°C (ice bath) Time (minutes)0 .150.30 0.451.001.302.002.30 3.00A 0.402 0.4370.4220.412 0.4170.3990.3860.3430.317-ln(A)  0.9110.8280.863 0.8870.8750.9190.9521.0701.149 Reaction at  ~23°C (room temperature) Time (minutes)00.150.300.451.001.302.002.303.00A 0.330 0.3000.2770.247 0.2660.1780.1360.1020.069-ln(A)  1.1091.2041.2841.3981.3241.7261.9952.283 2.674 Reaction at 50 °C (warm water) Time (minutes) 00.150.300.451.001.302.002.303.00A 0.240 0.2380.1870.1550.1340.0850.0160.0000.000-ln(A)  1.4271.4351.6771.8642.0102.4654.135– Include the graphs of the above data, and determine the slope of the line. Calculate k and enter it in the table below.   [pic 1]Figure 1. Graph of quantitative rates of bromination on diphenyl ether at 0ºC