Percent hydrolysis

Equation 2 rearranged for the concentration of HOX, shows that the percent hydrolysis increases with decreasing concentration of A/-halamine. 

Further, after 12 to 14 percent hydrolysis, limiting viscosity number of the derived, partially-hydrolyzed copolymer is 3 to 10 times larger than that of its nonionic precursor. The ratio of [n] after... 

TABLE 10. Elemental Assay, Percent Hydrolysis, and Limiting Viscosity lumber for Partially Hydrolysed Lignin Copolymer -... 

The percent hydrolysis of acetate must also be 0.57% because the equilibrium constant for the hydrolysis is the same as for NH+. 

In comparing the results of this problem with Problem 17.26, note that the percent hydrolysis of NH]j is greater in the presence of a hydrolyzing anion (like acetate). The reason is that the removal of some of the products of the two hydrolyses, H+ and OH-, by the water equilibrium reaction (H2O = H4" + OH-) allows both hydrolyses to proceed to an increasing extent. 

These non-gelling grades have a 98.0-98.8 percent hydrolysis range. Fully hydrolyzed grades are used for sizing spun synthetic yarns and synthetic/natural fiber blends. 

These grades have a 95.5 to 96.5 percent hydrolysis range. Properties lie between those of the fully and partially hydrolyzed grades. Intermediately hydrolyzed grades are used for sizing all types of spun yarns. 

Calculate [OH-], pH, and the percent hydrolysis for O.IO M solutions of (a) sodium acetate, NaCH3COO, and (b) sodium cyanide, NaCN. Both NaCH3COO and NaCN are soluble ionic salts that are completely dissociated in H2O. From the text, for CH3COO- = 5.6 X IQ-IO from Example 18-18, for CN- = 2.5 X IQ-. ... 

The percent hydrolysis for 0.10 M CN- (1.6%) is about 210 times greater than the percent hydrolysis for 0.10 M CH3COO- (0.0075%). In Table 18-9 we compare 0.10 M solutions of CH3COO-, CN-, and NH3 (the familiar molecular weak base). We see that... 

The basic ionization constant for hydrazine, N2H4, is 9.6 x 10 . What would be the percent hydrolysis of 0.100 M N2H5CI, a salt containing the acid ion conjugate to hydrazine base ... 

Since each CH3COO ion that hydrolyzes produces one OH ion, the concentration of OH at equilibrium is the same as the concentration of CH3COO that hydrolyzed. We can define the percent hydrolysis as... 

Calculate the pH of a 0.15 M solution of sodium acetate (CH3COONa). What is the percent hydrolysis ... 

Thus the solution is basic, as we would expect. The percent hydrolysis is given by... 

Comment The result shows that only a very small amount of the anion undergoes hydrolysis. Note that the calculation of percent hydrolysis takes the same form as the test for the approximation, which is valid in this case. 

Fig. 2-8. Time ior 5 percent hydrolysis of pyrophosphate (sodium salt) in a 1 percent (approximate) solution. Adapted from J. R. Van Wazer, Phosphorus and Its Compounds, Vol. 1, Interscience, New York, 1966, p. 454. Reprinted by permission of John Wiley Sons, Inc.

Hydrolysis is catalyzed by H. Examination of Fig. 2-8 shows that at 10°C the time for 5 percent hydrolysis of a pyrophosphate solution at pH 4 is about 1 year at pH 7 is many years and at pH 10 is over a century Of course, catalysis of the hydrolysis reaction by enzymes is important in nonsterile natural waters. Wastewater effluent and natural waters contain significant amounts of organically bound phosphate. Indeed, some estimates of the phosphate content of natural waters assign between 30 to 60 percent of the total phosphate to the organically bound category. 

Evaluation of the polymer s catalytic activity involved monitoring hydrolysis reactions using 50-fold molar excess of 23 with respect to the theoretical amount of functional groups present in each polymer. Figure 4 shows a plot of percent hydrolysis vs. time. Curves a, b, and c correspond to polymers P-12, P-13, and P-11, respectively. It is clear that curves a and b do not display a typical pseudo first-order kinetics. Only curve c displays Michaelis-Menton kinetics, indicating P-11 contains an active site that may bear some features of saturation kinetics (Table 5) wherein cooperative effects from juxtaposed ligands help to enhance the nucleophilicity of the serine-hydroxyl group (Scheme 12). 

Figure 4 Plot of percent hydrolysis vs. time for the hydrolysis of 23 in the presence of P-12 (curve a), P-13 (curve b), and P-11 (curve c).

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