INDUSTRIAL A N D ENGINEERING CHEMISTRY
September, 1923
determined for the float, becomes constant, and also the values of the weight of the solution analyzed, A , and the weight, WS, of the solvent added or evaporated from the solution. If the float is too heavy for the solution and the solvent must be evaporated from the solution, the value of WS takes on the negative sign. According to the calibration results,
G Wl
=
0.30451 ; therefore
G
is equal to 0.2334. The formula for determining the + G concentration of unknown solutions then becomes: ~
Wi
=
100 (0.2334)( A 4- W3) A 0.2334 ( A Wa)
+
-
-4test, of the accuracy of the method as compared with results obtained gravimetrically for the determination of nickel by the glyoxime method showed concordance. The results in terms of grams of anhydrous nickel sulfate per 100 grams solvent were as follows: 30.304 . . . . . . . ......... 30.296
30.250 30.178
Floating equilibrium method.. Gravimetric method . .
969
floating equilibrium method in analyzing solutions for concentration is therefore more accurate than the hydrometer gravity determinations. The values plotted on a curve (Fig. 1) show a comparison with those obtained by gravimetric analysis by Steele and Jackson.6 The values obtained by the float method are slightly higher than these, but this may be due to the difference in values obtained for the components owing to the different methods of analysis used. The float method agrees well with the gravimetric methods made in our own work, the float having been calibrated by the same method as used for the gravimetric data.
30,292 30.284
DISCUSSION OF RESULTS The data obtained on the solubility of the various hydrates of nickel sulfate are given in Table I. All weighings have been reduced to the vacuum basis. Comparison is shown between the float and gravimetric results. The gravimetric analyses are averages of three determinations. TPLBLE I-SC
OF iLUBILITIES CIP HYDRATES
Weight of Solution Temp. A c. 136.8331 -4.25 146.3774 -2.00 35.5239 0.00 125.2792 3.19 6 . 0 0 ( a ) 145.4360 108.8148 110.4139 112,3565 15.65 25. O O b ) 107.2881 3 0 . OO~LZ] b ) 101.7064 109.1731 105.3053 107.6976 (. C ). 31.71 107.0614 4 0 . 0 0 a) 121.3861 67.0706 50.00$$ 102.3786 ( b ) 110 2000 53.25 10511427 104.1877 58.21 103.4108 60.11 96.9927 79.75 136.3227 94.22
8
Weight of Solution Added Solvent A Wa 124.9331 118.7795 31.6771 120.2928 145.3731 108.6617 110.2466 126.0980 132.4285 126.0940 142.2885 136.8687 139.7399 142.9922 167.0780 92.8400 150.5640 161 7555 158:0395 159.1173 158 2371 162:9067 245.6684
T X E H Y D R A T € S OF N X U E L S U L F A T E
NICKEL SULFATE
GRAMSNiSO4 + (ANHYDROUS)
+
PI$R
100 G . WATER Float Gravimetric
23.366 26.189 28.884 30.304 30.292 35.491 40.469 40.720 43.719 43.546 43.439 45.299 47.329 47.727 52.267 52 075 54:041 55.389 55 567 64:476 72.597
TYPE OF SALT
23.543 26.087 28.765 30.253 35: i i 4 40.417
FIG.1
i
NiSOa. 7Ha0 (Green)
43:2i39
....
....
45.187 47.437 52:29l
i
NiS04'6Ha0
541009 J 55.177) 55.396 64.217 NiS04'6Ha0 (Green) 72.424)
I n checking with the gravimetric method, the results obtained indicate the applicability of the float method. If it is assumed that the density under standard conditions is a true measure of concentration, then the accuracy of the method depends upon temperature control and the weighings. The weighing of large samples for analysis obviates a painstaking care in the analysis by reducing the effect of small errors in weighing and procedure. Several drops of liquid excess will not influence the final results on such large samples, but the sensitivity of the float does not permit of a variation over one drop, since only one drop makes a decided difference in concentration. Ordinary precautions as to determinations of densities by float hydrometers apply equally well here. The time required for making an analysis is indeed very small when compared with the long gravimetric methods for determining the concentration of constituents present. The ordinary floating hydrometer type with an exposed stem protruding through the surface of the liquid can be used, but the sensitivity is not very great owing to the variation in the surface tension on the exposed stem. One drop of water on a float in equilibrium will cause a sinking, while the effect on an hydrometer float would be negligible. The
The possibilities of the application of the principle of floating equilibrium are very great. Where great accuracy is desired and neither time nor opportunity for making a gravimetric analysis is possible, this method suggests itself. Also, in the analysis for concentrations of solutions such as unstable organic compounds, which require exceedingly great care in analysis because of the unstableness or other difficulties encountered, the float method recommends itself, for when a float is once calibrated for the given solvent and solute, concentrations are easily determined. 0
J . Chem. SOC.(London), 86, 113 (1904).
A Remedy in Sight On several occasions we have called attention to the practice of certain so-called American universities who have offered academic degrees for sale. This campaign has had no success in America, but unfortunately attracted certain individuals in foreign countries much to the embairassment of America. A recent announcement gives reason for hope that the charter given in good faith by a state legislature and officially purchased by the principal offender in marketing degrees may be revoked. The spurious university in question has been cited to show cause why its charter should not be revoked. It is our earnest hope that it may be speedily revoked and this pernicious practice made impossible in future.
Earning Power of Research Recently, a corporation capitalized a t a very substantial figure closed its plants, dismissed its sales force, and practically retired from business. This failure is mainly attributable to the fact that a competitor succeeded in winning and holding certain foreign trade. The successful concern was able to do this because years ago he turned t o research and scientific control, whereas the unsuccessful concern, tardy in its recognition of science, was unfortunate in the selection of its scientificpersonnel, in the choice of its problems, and perhaps did not adequately support a scientific program. It is another instance of the difference between success and failure, success resting with science.
