Simple distillation evolution

The most reliable data are from studies of hydrogen evolution on mercury cathodes in acid solutions. This reaction has been studied most extensively over the years. The use of a renewable surface (a dropping mercury electrode, in which a new surface is formed every few seconds), our ability to purify the electrode by distillation, the long range of overpotentials over which the Tafel equation is applicable and the relatively simple mechanism of the reaction in this system all combine to give high credence to the conclusion that p = 0.5. This value has been used in almost all mechanistic studies in electrode kinetics and has led to consistent interpretations of the experimental behavior. It... 

Let s consider the following experiment a ternary mixture of composition x, Xg, Xq is submitted to simple differential distillation at constant pressure, as depicted in Figure 9.1-left. The time-evolution of the liquid composition describes a residue curve. Suppose that at the time t, the pot contains L moles of liquid of composition x/. If the vapour with the equilibrium composition y/ is removed at the rate V, then the component material balance over the time dt gives ... 

In a 1 L round-bottom flask, equipped with a condenser and a bubbler filled with DMSO, a solution of malonic acid (104.1 g, 1.0 mol), piperidinium acetate (from 0.85 g piperidine and 0.6 g acetic acid, 0.01 mol) and -octanal (64.0 g, 0.5 mol) in DMSO (500 mL) was stirred under nitrogen at room temperature for 20 min. Then the nitrogen was removed and the solution was heated on a steam bath, with stirring. A rapid evolution of CO2 was observed. Heating was maintained until the evolution of CO2 ceased (4 h). The solution was cooled to room temperature, poured into 1 L of cold water and extracted with diethyl ether. The combined extracts were washed with water, dried over anhydrous sodium sulfate and evaporated under reduced pressure. The crude product was purified by distillation under vacuum, using a simple, 30 cm Vigreaux column to give ( )-dec-3-enoic acid (73.1 g, 86% yield). 

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