Ethyl acetate, saponification rate

From which we calculate k. This method, the first one listed above, yields 8.3 L/mol min or 0.14L/mol s for the ethyl acetate saponification rate constant k As shown in Chapter 2, the initial time central difference method gives 8.3 L/mol min and the initial time polynomial method gives 8.8 L/mol min and the initial concentration method yields 3.8 L/mol min for the ethyl acetate saponification rate constant (see Table 2.4). 

In the ranges of the operating conditions tested, the overall crystal- growth rate coefficient of Na2HP04 measured in ISC, Vs. is higher systematically than that measured in FBC, Vu. by 15 to 20%, while the reaction rate constant of ethyl acetate saponification measured in the SCISR, Vs. is larger systematically than that measured in the STR, Vt> by about 20%. 

Figure 2.9 displays the equations describing the relationships between ethyl acetate concentration and time for the experiments shown in Figure 2.8. The top equation in Figure 2.9 is for an initial 0.1 mol/L ethyl acetate the middle equation is for an initial 0.05 mol/L ethyl acetate and, the bottom equation is for an initial 0.025 mol/L ethyl acetate. From these equations, we can calculate the initial reaction rate for ethyl acetate saponification. For 0.1 mol/L ethyl acetate, the equation is...

Our interest is in the initial rate of ethyl acetate saponification, which occurs at t = Therefore, setting t = 0 in the above equation gives us... 

We have now determined the reaction order of each reactant for ethyl acetate saponification via two procedures one, with respect to initial reactant concentration the other, with respect to initial reaction time. We have a choice with regard to the latter procedure we can calculate the reaction rate using a central difference algorithm or we can generate a polynomial equation describing the change in reactant concentration as a function of time, then differentiate that polynomial to obtain the reaction rate. Table 2.4 presents the results for each of these procedures for ethyl acetate saponification. So— which reaction rate equation is correct The more appropriate question is which reaction rate equation is valid The most valid reaction rate equation is the one based on initial reactant concentrations. The reaction rate equations based on initial reaction time are approximations of it. The sets of equations will be similar but not necessarily the same since we determined each set via a different experimental procedure. 

Table 2.4 contains the rate constant for ethyl acetate saponification as determined by the latter three methods above. 

Itil)lc6.1 Initial Reactant ( onecntration and Initial Reaction Rate for Ethyl Acetate Saponification at Constant Sodium Hydroxide ( onecntration and ariable Ethyl Acetate Concentiation ... 

Results of a laboratory analysis for the specific rate constant for the saponification of ethyl acetate by NaOH at 0 [ °C] are given below. One of the runs was performed with an electric stirrer, while the others were hand stirred. The results were analyzed by the differential and integral methods. Does the electric stirrer make a significant difference to the results Does the method of analysis of data make a significant difference ... 

Thus the rate of saponification of ethyl acetate with sodium hydroxide may be adequately modeled by a rate expression of the form... 

As a result of five limitations Mid restrictions given. Equation (1-1) is a rather hmited and confusing definition of the chemical reaction rate. For amplification of this point, consider the following steady-flow system in which the saponification of ethyl acetate is carried out. 

The type 1 and type 2 trisaccharide derivatives 265 and 264 were each converted into the free azido carboxylic acid in quantitative yields by selective hydrogenation over 5% palladium-on-carbon in ethyl acetate. Zemplen saponification gave the trisaccharide derivatives 268 and 269 (91 and 85%, respectively). Transfer of fucose from GDP-fucose, catalyzed by human milk -3/4- fucosyltransferases, to the type 1 and type 2 acceptors 268 (Scheme 44) and 269 (Scheme 45) proceeded at rates comparable to those of the natural substrates and afforded tetrasaccharides 270 and 274 in quantitative yields. From the azido tetrasaccliarides 270... 

These compounds are prepared starting from chloroace-tic acid or its ethyl ester. For chains longer than acetic, cyanoethylation and hydrolysis of the nitrile obtained leads to the propionic chain, alkylation with ethyl 4-bromobuty-rate and saponification leads to the butyric chain. The propanesulfonic chains are particularly accessible by means of ring opening of propane-sultone. 

Thus, the initial saponification rate for 0.1 mol/L ethyl acetate is 0.046 mol/L niin. Note that we are using the absolute value of d[EA]/dt since chemical reaction rates are positive. The initial saponification rates for 0.05 mol/L and 0.025 mol/L ethyl acetate are easily obtained from the equations shown in Figure 2.9. Those rates are... 

E14.6 The saponification reaction of ethyl acetate in solution of sodium hydroxide is rapid and the kinetics has been determined. The rate constant is given by ... 

The rate of esterification of acetic, propionic, citric, butyric, malic, succinic, lactic, and tartaric acids at three different pH s over a 30- to 60-day period was determined by Espil and Peynaud (1936). They showed that none of the ethyl esters of the polyhydric alcohols contribute to the aroma and would not even if present at ten times their normal amounts. Tomaghelli (1937) studied the rate of esterification of the system acetic acid-ethyl alcohol and that of saponification of the system ethyl acetate-water at 100° C. (212° F.) for 500 hours and at 150° C. (302° F.) for 320 hours. 

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