T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
Dec., 1920
DISSOLVED SOLIDS
STATE
HARDNESS O F SURFACE WATERS BY STATES (Parts per Million) Hardness as CaCOa Equivalent t o Dissolved solids Ca and Mg NOTES AND
Alabama 70-90 Arizona 500-700 Arkansas 600 Ca1ifor:nia: Northern part 80-250 400-600 Southern part Great Basin drainage 200-~00,000
15-40 200-300 200
Colorado Connecticut Delaware District of Columbia Florid?. Georgia Idaho Illinois
150-700 50-100 80 100
100-400 25-50 40 40
150 60-80 100-200 250-300
100 1540 60-125 200-250
40-200 200-300 60-300-0
Indiana 250-350 200-300 Iowa 225-300 190-230 Kansas: Drainage t o Missouri River 3 5 0-5 50 225-350 Drainage t o Arkansas River 400, ~ O O ~ ~ O O 250,500-800 O Kentucky 100 70 Louisiana 500 255 Maine 20-50 5-20 Maryland 100-150 50-75 Massachusetts 50-60 15-25 Michigan 250 200 Minnesota: Northern 100-1 50 70-100 Central a n d southern 250-500 200-350 Missisr;ippi 70-90 15-40 Missouri 350 200 300-600 200-300 Montana 300-500 150-300 Nebraska Nevada: 100-200 30-100 Mountainous area Lowland area 2000'-30,000 200-300 20-50 5-20 New Hampshire 100-1 50 New Jersey 50-100 500-3000 250-1500 New Mexico 50-100 New York 100-150 North Carolina 60-80 15-40 200-600 300-800 North Dakota Ohio 250-350 200-300 Oklahoma 1000-3000 500-1500 Oregon 80-125 40-60 Pennsylvania 100-150 50-100 Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming: Mountainous area Lowland area
30-50 i 0-90 300-800 100 300, 1000-2000 500-1000 30-50 70-90 60-125 100-150 100
200 800-1000
5-25 1540 200-600 70 200, 500-1500 200-300 5-25 15-40 20-60 70-100 50 150 500-600
100 - i i b ' N a 150 N a
.....
100 N a Higher concentrations practically all N a salts
..... . t . . .
.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..... .
.
I
.
.
HighinNasalts High in N~ salts
..... ..... ..... .. .. .. .. ..
..... ..... ..... ..... ,.... ..... High';;
...N . .a s a l t s .. .. .. .. .. ... ... . ..... I .
High N a ' Acid . . waters ...
at
some places less in western part
..... ..... .....
High'& N a 100-250 N a
.. .. .. .. ..
..... .....
.....
..... I
.
.
.
.
the middle-west states bordering the Mississippi a n d t o the east. Hard and strongly alkaline water is found in the area outlined roughly by North Dakota, Arkansas, Louisiana, Texas, Arizona, and the southern part of California. THE DETERMINATION OF ACETIC ACID IN PYROLIGNEOUS ACID By V. E. Grotlisch LEATIIER
AND
PAPER LABORATORY, BUREAUO F CHEMISTRY, AGRICULTURE, WASHINGTON, D. C. Received July 17, 1920
u. s.
1183
of dissolved tars, phenols, and similar compounds than that obtained in hardwood distillation, as shown by the deep red color of the liquor and the dark brown acetate of lime obtained therefrom. Direct titration of the liquor with alkali was impracticable and impossible, as no end-point could be seen with any certainty, owing both t o the color Of the solution, even when much diluted, and also t o the tars and phenolic bodies in solution. A search of the literature a t t h a t time failed t o give a method which was directly applicable t o such material. Pickettl has recently described a method in which xylene was used t o hasten the complete distillation of the acetic acid in the analysis of acetates by distillation from phosphoric acid. The use of xylene in the analysis of pyroligneous acid, for a somewhat different purpose, was suggested in 1915 by Mr. M. G. Donk, then of the Bureau of Chemistry, in correspondence between himself and the Bureau. The following method in its present form was evolved by the author and has been used in this laboratory since 1918. The xylene is used primarily t o effect a partial separation of the acetic acid from the tars, phenols, and other impurities. The separation is not complete, however, so t h a t in order to obtain really accurate results subsequent treatment of the distillate is necessary. This method thus has the advantage of giving a rapid, direct approximation of the quantity of acetic acid in a sample of pyroligneous acid, from which an accurate determination of the same can subsequently be obtained. The following observations were the basis of the method: (I) Xylene (b. p. 138' to 143O C.), which is immiscible with water, readily dissolves both the acetic acid and the impurities present in pyroligneous acid, but does not dissolve sodium acetate. The tars and phenols present are only slightly volatile a t the temperature of boiling xylene, which is above the boiling points of acetic and propionic acids. Accordingly, if the xylene is present in large enough excess in a distillation mixture, the distillate a t a certain point will contain all the acetic and propionic acids, with only a small proportion of the other bodies which interfere with the titration of the distillate, which gives a very close approximation of the quantity of acetic acid present. (2) The tars, phenols, aldehydes, etc., which are present in pyroligneous acid are easily and completely oxidizable t o carbon dioxide by alkaline potassium permanganate, which does not affect sodium acetate. Elimination of the products of the oxidation reaction leaves a pure solution of sodium acetate.
PROCEDURE DE-
PARTMENT OF
I n a n investigation of the yields of various byproducts obtained along with wood turpentine in t h e destructive distillation of certain resinous woods of western origin, carried out in the Bureau of Chemistry several years ago, i t was found desirable t o determine directly the percentage of acetic acid in t h e crude pyroligneous acid. This material, when obtained from highly resinous wood, such as the "fat" stump wood used in the commercial production of wood turpentine, contained considerably larger percentages
The following procedure has been adopted a s t,be most convenient, rapid, and least liable t o introduce errors: Place 1 2 0 cc. of xylene (which has previoiisly been distilled from solid sodium hydroxide) in a 7 0 0 cc. long-neck, round-bottom flask, pipet in I O cc. ol' the clear acid liquor, free from suspended tarry matter, and add a liberal quantity of finely broken pumice stone t o prevent violent bumping during the distillation. Connect the flask t o a Io-in. spiral glass condenser, clamped vertically or nearly so, and having an outflow tube about 8 in. long, by means of a tube such as is shown in Fig. I , which prevents entrainment 1
THIS JOURNAL, 12 (1920), 570.
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T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
Vol.
12,
NO. 1 2
of unvaporized particles of xylene containing impurities. Cork stoppers must be used on account of the solvent action of xylene on rubber.
into a 400-cc. beaker, washing the xylene twice with a little distilled water. Boil down t o about 7 0 cc., avoiding loss by spattering. Add I O O cc. distilled Distil slowly with water and again boil down t o 7 0 cc., and repeat this a small flame a t once more, t o insure complete removal of all volatile first, collecting the esters, acetone, or other volatiie bodies. After cooldistillate in a 100-cc. ing, make alkaline with a few drops of sodium hydroxgraduated cylinder ide solution, and add about 15 cc. of a strong solution or Erlenmeyer flask, of potassium permanganate. Cover with a watch containing a few cc. glass and place on a steam bath for several hours, of distilled water t o preventing evaporation t o dryness by addition of y/6“. . dian, seal the end of the water, if necessary. The permanganate oxidizes t h e g / a s s fibmy c o n d e n s e r tube. organic impurities which cause the excess acidity, with After all water has the formation of a copious precipitate of manganese dioxide. The quantity of permanganate required will %’ b/own;o o n been distilled over, vary according t o the nature of the original acid liquor. O,bko6lt-e sides. increase the heat and continue distilla- After standing on the steam bath for 3 hrs. there 5; angle, hole, grovnd o f P o , __ fir . ~ e ~ / e &n. d tion until the total should still be enough undecomposed permanganate FIG.1 distillate amounts t o left t o give the clear solution a distinct light purple 7 5 cc., consisting of I O cc. of an aqueous layer a t the color. Wash the solution and bottom and 65 cc. of xylene, which is colored a faint yellow by some impurities which have been carried precipitate into a 300-cc., glass-stoppered over. It has been found t h a t by the time 7 5 cc. of volumetric flask, make up t o mark, total distillate are obtained all acetic acid and the and thoroughly shake. Filhomologous formic and propionic acids have been dister, with light suction, tilled off. Further distillation continues t o drive over acid bodies, which have in every case failed t o give through a layer of washed a test, on neutralization, for acetate, formate, or pro- asbestos on a Hirsch porcepionate, and are completely decomposed by potassium lain funnel, discarding the permanganate. No error in the final results will be first 50 cc. of filtrate t o introduced, however, if a little more distillate is col- insure t h a t the collected portion is of the same conlected. centration as the original A very delicate test for acetatel and the homologous volumetric solution. Pipet salts (not for the free acid) is obtained by the use of a 200 cc. of the remaining solution containing cupric chloride and sodium chloride. A solution containing 7 0 g. of the former and 50 g. of filtrate into a beaker, and t h e latter per liter of distilled water gave very satis- evaporate on a steam bath factory results. It should be made up several days in or over a low flame t o advance and allowed t o settle, decanting off the clear about 7 5 cc. Cool t o about solution for use. If the fine, light green precipitate 15’ C. and acidify with does not form a t once, bring t o a boil and allow t o a few drops of concentrated A Add hydrostand I O min. One or two drops of 2 5 per cent sulfuric acid. gen peroxide, a few drops acetic acid should clear up the solution. This reagent a t a time with stirring, t o will detect one part of sodium acetatein 5000 parts of destroy t h e permanganate. distilled water. The solution is clear and Wash the entire distillate into a 500-cc. Erlenmeyer flask and titrate t o neutrality with 0.; N sodium colorless, and should still be hydroxide, using about I O drops of a solution of phenol- slightly acid. Add a slight excess of phthalein in methyl alcohol as indicator. I n case of FIQ. 2 saturated barium hydroxide over-titration titrate back with sulfuric acid. Toward t h e end of the titration the liquid must be well shaken solution, t o precipitate the A--8 OZ., wide-mouth bottle. after each addition of alkali t o free the acid from solu- sulfuric acid, the manganese, B-2 in. funnel. C-Small CaCh tube charged with caustic soda tion in the xylene. This titration gives only a close and t h e carbon dioxide and soda lime approximation of the exact quantity of acetic acid formed through oxidation of present, as pointed out. The end-point is fairly sharp, the organic matter. An excess can be shown by adding b u t the pink color of the indicator fades quite rapidly, a drop of sodium sulfate solution, when a white preand the aqueous portion gradually turns brownish, cipitate of barium sulfate will be formed in the clear due probably t o absorption of oxygen by the phenolic supernatant liquid. Again evaporate t o small volume on the steam bath, filter, and wash free from bodies. Now separate the aqueous portion from the xylene acetate with warm, previously boiled, distilled water, * J . Chem. SOC., 1878, 577, or Prescott and Johnson, “Qualitative keeping air containing COz away from the filtrate. Chemical Analysis,’’ 7th Ed., p. 2 5 8 . The apparatus sketched in Fig. 2 was used for this
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I
Dec., 1920
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
purpose with satisfactory results. Before filtering, the bottle is filled with COz-free air by drawing air slowly through Tube C into t h e bottle. Wash the precipitate until the bottle is full, testing a final portion of t h e filtrate with the reagent described previously, t o insure complete removal of acetate from the precipitate. Wash the contents of the bottle into a joo-cc. roundbottom flask containing I O cc. of sirupy, 8j per cent phosphoric acid (free from volatile acids), and add a few pieces of pumice. Distil off the acetic acid through t h e condenser used for t h e first distillation, sealing t h e end with a little distilled water, into a joo cc. Erlenmeyer flask. When the volume of the liquid in t h e distillation flask has been reduced t o about 45 cc. and the liquid begins t o bump and froth, remove the flame and allow the flask t o cool for a few minutes, taking care t h a t the distillate does not suck back into t h e flask. Then add 2 5 cc. of warm distilled water, or t h e last washings in case acetate was still found in t h e filtrate after the bottle was full, and distil again t o the same limit, repeating this operation twice more in order t o insure complete removal of the acetic acid from t h e distilling flask.l Wash out the condenser into t h e receiving flask and titrate t o neutrality. The quantity of standard sodium hydroxide used, multiplied b y 1.5, represents the free acetic acid in the I O cc. of acid liquor. The xylene portions of the first distillate and also t h e residues from t h e first distillation may be collected, separately, for further use. They should be washed with a concentrated solution of sodium hydroxide and finally distilled over caustic soda. EXPERIMEXTAL RESULTS
I n order t o work out the above method and prove i t s reliability, various solutions containing acetic acid and acetates, as well as propionic acid, were made up, a n d different quantities of various organic substances, such as would probably be present in crude pyroligneous acid, were added, t o give test solutions which might approach in their composition t h a t of the pyroligneous acid, or a t least contain some of the foreign bodies therein. These were analyzed, with the following results. EXPT. I-Ten-cc. portions, of a number of different samples of crude pyroligneous acid were pipetted into 120-cc. portions of C. P. xylene and distilled as outlined above. The distillates were collected in fractions, as; follows: first, a jo-CC. fraction, then in j-cc. portions until a total of 90 cc. was collected. Titration of these fractions showed t h a t all contained acid i n diminishing quantity. Those collected after a total of 7 0 cc. had passed over failed in every case t o give a test for acetate, after neutralization. On evaporation t o dryness, brown, greasy residues were obtained, i n which no crystals could be seen under a powerful magnifying glass. On distilling a 120-cc. portion of a composite xylene residue, obtained by combining the residues after 7 5 cc. of distillate were collected, 1 If any considerable number of determiuntions are t o be made, the distillation procedure and apparatus described in Allen’s “Commercial Organic Analysis,” i, 4th Ed., 508, or in Sherman’s “Organic Analysis,” p. 130, can be advantageously used.
118;
with I O cc. of distilled water as before, the distillate neutralized 1.0 cc. of 0. j N sodium hydroxide, ’ but gave no test for acetate. EXPT. 11-Ten cc. of a dilute solution of acetic acid, equivalent t o 16.24 cc. of 0.5 N sodium hydroxide (mean of three titrations), together with 6 0 cc. of freshly redistilled, neutral xylene, were added t o 60 cc. of the xylene residue mentioned above, and distilled until a total of 75 cc. distillate had been collected. Titration required 16.96 cc. of the standard alkali, instead of the theoretical 16.24 cc. After separation of the aqueous portion and treatment with permanganate, as outlined, the final distillate from phosphoric acid of a n aliquot equivalent t o one-half the original quantity of acid used required 8.10 cc. of the standard alkali for neutralization. Theoretical, 8.12 cc. EXPT. 111-Three solutions of sodium acetate, made by titrating 20-cc. portions of the same acetic acid (mean, 32.49 cc. alkali), were made up t o 2 5 0 cc. in volumetric flasks. There were added, respectively, 4 cc., j cc., and 6 cc. each of methyl alcohol, acetone, and methyl acetate, and in addition a little pyrogallol t o No. 2 and a little pyrocatechol t o No. 3. Two IOOcc. portions, designated as a and b , were pipetted out and boiled down t o about 40 cc., this being repeated. They were then treated with the permanganate, etc. The whole solution was kept for the final distillation, care being taken t o wash the manganese dioxide precipitate until all traces of acetate and permanganate were recovered in the filtrate. Final distillation from phosphoric acid gave the following results, the theoretical quantity of sodium hydroxide required being two-fifths of 32-49 cc., or 13.00 cc. TABLEI Solution 1Q lb 20 2b 3a 3b
NaOH Required for Final Titration cc. 13.10 13.14 13.03 12.92 13.05 12.95
Difference from Theoretical
cc.
+o.
10
i o . 14
i0.03 -0.08
io.05 -0.05
EXPT. Iv-Expt. I1 was repeated, several cc. each of methyl alcohol, acetone, and methyl acetate, and 0.2 j g. each of pyrogallol and pyrocatechol being added t o the distillation mixture. The first distillate required 16.80 cc. of 0.5 N alkali. After several boilings and oxidation with permanganate, the final distillate from phosphoric acid of an aliquot portion equivalent t o one-half the quantity of acid taken neutralized 8.13 cc. of alkali. EXPT. v-The experiment was repeated, using in one case 3 cc. of beechwood creosote and in the other I j g 06 crystalline phenol. The first distillates required, respectively, 16.80 and 17.18 cc. of 0 . j N alkali. After treatment with permanganate, etc., the final distillates from aliquots equivalent t o two-thirds of t h e quantity of acetic acid originally taken required 16.28 and 16.00 cc. of the alkali, proving t h a t phenol and cresol are eliminated by the permanganate oxidation. EXPT. VI-A solution containing both acetic and propionic acid, in the ratio of 4: I , was used for the same
