The problem of dilution in colorimetric H-ion measurements 11-Use of Isohydric Indicators and Superpure Water for Accurate Measurement of Hydrogen-Ion Concentrations and Salt 1,2

Acree, S. F.; Fawcett, Edna H.

doi:10.1021/ac50069a033

Cited by 14 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the classical dissociation constant of acetic acid in 0.1 M potassium chloride solution has been determined kinetically and electrometrically (9) and the values found are 2.90 and 2.84 X 10~5, respectively. Both methods involve assumptions, but 1 For the corresponding equations in terms of activity of hydrogen ion, see refer- the fact that the results agree within 3 per cent indicates the validity of the assumptions. If we take Kc for acetic acid as 2.90 X 10~5, and prepare a solution 0.0100 M in sodium acetate, 0.0100 M in acetic acid, and 0.09 M in potassium chloride, we know its hydrogen-ion concentration within 3 per cent (0.01 pH unit) from equation 2.…”

Section: Hi + H20mentioning

confidence: 96%

“…There is given in table 1 the information necessary for the preparation of standard buffer solutions covering the range from 1 X 10-2 to 2 X 10~7 M in hydrogen-ion concentration. The second column of the table contains the thermodynamic dissociation constant, given for purposes of comparison; the third, the classical dissociation constant in 0.1 M potassium TABLE 1 The classical dissociation constants of certain acids in 0.1 M potassium chloride* solution at 25°C. Methyl orange 4.27 X 10-4 1.46 X 10 ~4 2.38 X 10"4 Benzoic............. 6.312 X 10~6 10.12 X 10-6 Bromophenol blue 14.9 X 10"s Bromocresol green 3.07 X 10-« Acetic.............. 1.745 X 10 "6 2.90 X "6 Methyl red chloride solution, as determined electrometrically or kinetically in this laboratory.…”

Section: Hi + H20mentioning

confidence: 99%

“…In measuring the hydrogen-ion concentration of an unbuffered or weakly buffered solution it is necessary first of all to determine whether or not the addition of the indicator has changed the hydrogen-ion concentration. To do this one must carry out a series of measurements at several indicator concentrations and several acid-base ratios of the indicator (1,4,11,13).…”

Section: 5mentioning

confidence: 99%

See 2 more Smart Citations

The Colorimetric Determination of Hydrogen-ion Concentration in Aqueous Solution.

Kilpatrick¹

1935

Chem. Rev.

View full text Add to dashboard Cite

Section: Hi + H20mentioning

confidence: 96%

Section: Hi + H20mentioning

confidence: 99%

Section: 5mentioning

confidence: 99%

See 1 more Smart Citation

The Colorimetric Determination of Hydrogen-ion Concentration in Aqueous Solution.

Kilpatrick¹

1935

Chem. Rev.

View full text Add to dashboard Cite

“…In the ball mill hydration an H20/Ca3Si05 weight ratio of 9 was used. Complete hydration was obtained in 6 days, and the reaction progressed according to the equation 2Ca3Si05 + 6H20 = Ca3Si207.3H20(A) + 3Ca(OH), (1) The calcium silicate hydrate, Ca3Si2(>7.3H20(A), was afwiilite. The paste was hydrated for 2 years, at the end of which it contained only about 0.5% unhydrated tricalcium silicate.…”

Section: Calcium Silicate Hydrate-calcium Hydroxide Mixturesmentioning

confidence: 99%

Investigation of Franke Method of Determining Free Calcium Hydroxide and Free Calcium Oxide

Pressler¹,

Brunauer²,

Kantro³

1956

Anal. Chem.

View full text Add to dashboard Cite

“…Using 1900 ml. in each Mason jar and in each battery jar in a series of experiments (1) with distilled water and (2) with colored surface water, the settling time in minutes with the stirred jars was much less than the settling time in the Mason jars (Table V). Two series of tests were made using city water (Table VI) in one of which sulfuric acid was added to lower the pH of the water treated.…”

Section: Correlation Of Results Of Jar Testsmentioning

confidence: 95%

Formation of Floc by Aluminum Sulfate

Black¹,

Rice²,

Barton³

1933

Ind. Eng. Chem.

View full text Add to dashboard Cite

A N Y fundamentally The indicator solutions formerly used gave a atid (2) the size of the reaction important a d v a n c e s p~ in unbu#ered solu~ions more than tiE vessels. Their values for pI1 h a v e b e e n m a d e in were determined by the coloritrue p H as determined with properly adjusted lnetric water purification practice in the past thirty years, not so much (kohydrie) indicators. At l e d 2 liters of water used were exceedingly dilute, b e c a u s e of the introduction of should be used for all jar tests for plant control varying from 0.0002 . $ I to 0.002 new m e t h o d s as h e c a u s e of in order to eliminate effects due to the size of the M , and were in most cases very a better understanding of the cessel. slightly buffered. Recent work various principles involved in by Xolthoff and Kameda (/I), the methods o r i g i n a l l y emSulfate in amounts front 25 lo 250 p . p . ni. and Fudge (8), Sclllegel ployed. ezlend the zone of rapid floc formation for to the and Steuher ( l o ) , F~~~~~~ and The r e s e a r c h work o f t h e acid s&. Chloride ion ezerts relatiliely little Acree ( 5 ) , and others has shown colloid chemist explains the proceffect below 6.5 p H but does eslend the zone that serious errors may result in ess of coaguliation ( f o r m a t i o n toward the si&. ~~b~~~ the determination of the pH of of floc) for the removal of color results are.found to hold on a serniplant scale. unbuffered solutions by the color turbidity. Colloid chemistry orimetric method unless certain has showii t h a t t h e o r i g i n a l Conlin~llous stirrirt!f is absolutely rwcessary precautions are taken. The pH ideas concerning the action of the conduct of jar tests which will check euch of tile indicator solution itself floc were largely incorrect, but other and give accurate data for plant operation.must not he very different from that a more or less fortuitous that of the unbuffered soluti~n choice of coagulants was a happy treated o r it will p r o d u c e a one. Even with full knowledge of tlie phenomena, no better correspnding change in the pH of the solution. A coloricoagulants have been found. Saville (9) shows that the color mctric method for adjusting indicator solutions described by present in natural waters is colloidal.Acree and Fswcett (1) permits adjustment to any desired Miller (7) seems to have been the first to p i n t out the ef-pH value or series of values within the useful range of the ficient role of the trivalent aluminum and ferric ions in neu-particular indicator. It is thus possihio to employ an inditralioiiig and precipitating the negatively charged color col-cator solution termed "isohydric" of approximately the same loids, and to conclude that the absorptive property of the pII value as that of the solution being tested. Isohydric indigehtinous floc plays, as a rule, a relatively unimportant part cator solut.ions are recommended wherever accurate results in the process. on unbuffered solutions are desired. This p i n t becomes of Miller summarizes his own work together with t...

show abstract

The problem of dilution in colorimetric H-ion measurements 11-Use of Isohydric Indicators and Superpure Water for Accurate Measurement of Hydrogen-Ion Concentrations and Salt 1,2

Cited by 14 publications

References 0 publications

The Colorimetric Determination of Hydrogen-ion Concentration in Aqueous Solution.

The Colorimetric Determination of Hydrogen-ion Concentration in Aqueous Solution.

Investigation of Franke Method of Determining Free Calcium Hydroxide and Free Calcium Oxide

Formation of Floc by Aluminum Sulfate

Contact Info

Product

Resources

About