A. V. Tuumlets [Kinet. and Catal., 5, XXXXXXXXXX)] studied the kinetics of the reaction of ethyl magnesium bromide with pinacolin. He used a calorimetric technique to monitor the progress of the...

A. V. Tuumlets [Kinet. and Catal., 5, 71 (1964)] studied the kinetics of the reaction of ethyl magnesium bromide with pinacolin. He used a calorimetric technique to monitor the progress of the reaction. The overall temperature increase of the reaction mixture was less than a degree. Hence, one does not need to worry about the dependence of the rate constant on temperature. Mixture temperatures were determined with a sensitive potentiometer. The data that follow have been corrected to allow for heat losses from the system (i.e., adiabatic operation of the batch reactor may be assumed). The reaction was carried out in diethyl ether solution using initial concentrations of Mg Br and pinacolin of 0.403 and 0.01 mol/L, respectively. The stoichiometery of the reaction may be represented as A + B ? C Changes in the potentiometer reading may be assumed to be proportional to the temperature change in the reaction mixture. Determine the order of the reaction with respect to pinacolin and the apparent rate constant. Use two methods of analysis: (a) An approach based on the generalized physical properties relation that employs the reading at infinite time. (b) An approach combining the generalized physical properties relation with Guggenheim’s method. Discuss the relative merits of these approaches. Unfortunately, the potentiometer reading at time zero is not known with sufficient accuracy that it could be used with confidence in your analysis.