Calculation of successive formation constants from polarographic data using a high-speed digital computer

1967 ◽  
Vol 39 (10) ◽  
pp. 1072-1079 ◽  
Author(s):  
Kozo. Momoki ◽  
Hisakuni. Sato ◽  
Hisao. Ogawa
Keyword(s):  
Digital Computer ◽  
High Speed ◽  
Formation Constants ◽  
Successive Formation

STUDIES ON THE SOLUBLE INTERMEDIATES IN THE HYDROLYSIS OF DIMETHYLTIN DICHLORIDE: EQUILIBRIUM CONSTANT FITTING WITH A HIGH SPEED DIGITAL COMPUTER

1964 ◽  
Vol 42 (4) ◽  
pp. 781-791 ◽  
Author(s):  
R. Stuart Tobias ◽  
M. Yasuda
Keyword(s):  
Aqueous Solution ◽  
Digital Computer ◽  
High Speed ◽  
Chloride Ion ◽  
Formation Constants ◽  
Data Sets ◽  
Ionic Strength Effect ◽  
Low Concentrations ◽  
Hydrolysis Of ◽  
Titration Technique

The hydrolysis of (CH3)2SnCl2 has been studied in a medium 0.1 M in (Na+)Cl− by a potentiometric titration technique. The complexes formed by the hydrolysis reactions together with their formation constants have been determined by analysis of the 394 data sets using a high speed digital computer. The data can be fitted equally well over the range pH 1.5 to 9 by the four formation constants for (CH3)2SnOH+ (log *β11 = −3.245 ± 0.004), [(CH3)2SnOH]2+2 (log *β22 = −5.00 ± 0.02), (CH3)2Sn(OH)2 (log *β21 = −8.516 ± 0.004), and [(CH3)2Sn]4(OH)6+2 (log *β64 = −16.85 ± 0.02) or by the five constants for (CH3)2SnOH+ (log *β11 = −3.251 ± 0.004), [(CH3)2SnOH]2+2 (log *β22 = −5.05 ± 0.02), (CH3)2Sn(OH)2 (log *β21 = −8.535 ± 0.005), ((CH3)2Sn)2(OH)3+ (log *β32 = −9.81 ± 0.01), and ((CH3)2Sn)3(OH)4+2 (log *β43 = −11.52 ± 0.03). Thus there is little question about the existence in the solutions of the simple monohydroxo complex and its dimer or of the neutral dihydroxide. Only very low concentrations of species containing more than four tin atoms can exist in aqueous solution. In addition, the data determined previously for the hydrolysis of (CH3)2Sn(ClO4)2 in a medium 3.0 M in (Na+)ClO4− have been refined by the least squares procedure. These 762 data sets can also be fitted equally well by the set of constants log *β11 = −3.55 ± 0.01, log *β22 = −4.52 ± 0.01, log *β21 = −9.00 ± 0.01, and log *β64 = −16.14 ± 0.03 or log *β11 = −3.54 ± 0.01, log *β22 = −4.60 ± 0.02, log *β21 = −8.98 ± 0.01, log *β32 = −9.76 ± 0.06, and log *β43 = −10.40 ± 0.05. The tendency of dimethyltin dichloride to form polycondensed species in aqueous solution is slight, and there is no evidence for the formation of large rings or chains. The solid stannoxane which precipitates from chloride solution was studied by infrared and X-ray powder photography and is essentially the same as the compound obtained by reaction of (CH3)2SnO and (CH3)2SnCl2 in a 1:1 mole ratio in 95% ethanol. This corresponds to a slightly different product than that obtained by a 1:1 reaction of these compounds in benzene which gives ((CH3)2SnCl)2O. This is in accord with the observation that precipitation occurs only at a pH higher than that at which ((CH3)2SnOH)2+2 has attained the maximum concentration, and hence precipitation is occasioned by the formation of larger polycondensed species. A comparison of the perchlorate and chloride data also indicates that the tendency to form polycondensed species is reduced by the presence bf chloride ion. This is partially an ionic strength effect and partially a result of chloride complexing of the simple aquodimethyltin (IV) ion, and the first chloro-complexing constant was Estimated to be 28 1. mole−1.

The Wall Effect in Cavity Flow

1966 ◽  
Vol 88 (1) ◽  
pp. 132-136 ◽  
Author(s):  
D. K. Ai
Keyword(s):  
Flow Field ◽  
Flat Plate ◽  
Integral Equations ◽  
Nonlinear Theory ◽  
Digital Computer ◽  
High Speed ◽  
Cavity Flow ◽  
Channel Width ◽  
Wall Effect ◽  
Plate Location

A nonlinear theory for the calculation of the flow field of an oblique flat plate under blockage condition is given using the techniques of integral equations. Numerical results are obtained with the aid of a high-speed digital computer for the plate situated midchannel at values of the angle of attack from 10 to 90 deg and the channel width-chord ratio from 3 to 20. Although the theory is developed for arbitrary plate location, the midchannel case is of great interest due to the fact that most of the tests are performed at this position.

The Calibration of Thermocouples by Freezing-Point Baths and Empirical Equations

1959 ◽  
Vol 81 (2) ◽  
pp. 177-188 ◽  
Author(s):  
R. P. Benedict
Keyword(s):  
Digital Computer ◽  
High Speed ◽  
Freezing Point ◽  
Individual Characteristics ◽  
Empirical Equations ◽  
Test Results ◽  
Calibration System ◽  
Temperature Range ◽  
Experimental Values ◽  
The Individual

A calibration system is described which is based on the use of a few precisely determined experimental values obtained from freezing-point baths. Characteristics of the individual thermocouples at intermediate points are obtained by passing empirical equations of prescribed form through the test values. A program is reviewed, by which a high-speed digital computer accomplishes the necessary conversions, curve fittings, comparisons of individual characteristics with arbitrary reference tables, and the printing out of a table of differences. Test results for a series of iron-constantan thermocouples, over the temperature range 32–1225 F, are presented to illustrate the use of the system and the uncertainties involved. Comparisons are drawn between these results and those obtained by other methods.

Balancing of High Speed Machinery

1967 ◽  
Vol 89 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Chi-Yeh Han
Keyword(s):  
Phase Angle ◽  
Analytical Method ◽  
Digital Computer ◽  
High Speed ◽  
Mechanical Systems ◽  
Constant Speed ◽  
Mass Moment ◽  
Balance Weight ◽  
Optimal Values ◽  
Complete Revolution

An analytical method for optimal balancing of the shaking forces and the shaking moments of force of any plane mechanism driven by a constant speed shaft is developed. The optimal values of phase angle and mass moment of the balance weight on the driving shaft are ascertained, such that the variation of load on the machine supports due to shaking forces and shaking moments of force will be a mininum through a complete revolution of the driving shaft. Using a digital computer, this method is applicable to complicated mechanical systems; an illustrative example follows the analysis.

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