scholarly journals THE WEIGHT OF A FALLING DROP AND THE LAWS OF TATE; XIV. THE DROP WEIGHTS OF AQUEOUS SOLUTIONS OF THE SALTS OF ORGANIC ACIDS.

1913 ◽  
Vol 35 (11) ◽  
pp. 1759-1767 ◽  
Author(s):  
J. Livingston R. Morgan ◽  
Walter W. McKirahan
Keyword(s):  
Organic Acids ◽  
Aqueous Solutions ◽  
Salts Of Organic Acids

The metachors of polyvalent and associated electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1079-1089
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský ◽  
Jana Žilková
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Oxalic Acid ◽  
Organic Acids ◽  
Aqueous Solutions ◽  
Preceding Paper ◽  
Weak Electrolytes ◽  
Direct Proportionality ◽  
Very High

The quantity metachor introduced in the preceding paper was evaluated from the experimental data on surface tension of the aqueous solutions for a set of polyvalent and weak electrolytes. The almost complete concentration independence of the metachor and its direct proportionality to the number of the free charges in a dissociated molecule (observed and theoretically substantiated in the above cited paper for strong 1,1-, 1,2- and 2,1-valent electrolytes) has been verified in the present paper also for electrolytes of the higher valency types. The metachor values of fully dissociated 1,1-, 1,2-, 1,3- and 1,4-valent electrolytes follow a ratio (5 ± 1) : (10 ± 1.5) : 15 : 22 cm3 mol-1. Association of the electrolytes decreases correspondingly the metachor value as one can see on the case of electrolytes with bulky ions (NH4SCN, KCH3COO, Na2S2O3, hexacyanoferrates(II) or with the free acids H2SO4, H2CrO4, H3PO4 etc. A weak, in the investigated concentration range neglibility dissociated oxalic acid, consisting of small hydrated hydrophilic molecules, exhibits metachor values close to zero. Dibasic organic acids with a larger number of hydrophobic CH2 groups reach very high negative metachor values, however, their salts again possess metachor values close to 10 cm3 mol-1 - in accordance with the values found for strong 1,2-valent electrolytes. The metachors of ZnCl2 and CdCl2 decrease sharply from the last mentioned value, with increasing concentration while the metachor value of zinc perchlorate remains unchanged at the level corresponding to the fully dissociated salt. This is in agreement with the well known sequence of tendency of the d10-cations to form complexes with the Cl- and ClO-4 anions. All these facts have verified that the metachor can be, in principle, applied for a diagnostic states of the electrolytes in aqueous solutions.

Proflavine binding and release by sensitive and resistant Bacillus subtilis

1970 ◽  
Vol 16 (10) ◽  
pp. 973-981
Author(s):  
Gy. Barabas ◽  
B. M. Mehta ◽  
D. J. Kushner
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Organic Acids ◽  
Resistant Strain ◽  
Binding Capacity ◽  
Sensitive Strain ◽  
Growth Media ◽  
Sodium Salts ◽  
Salts Of Organic Acids ◽  
Resistant Cells

Proflavine binding of a sensitive strain of Bacillus subtilis and of a resistant strain derived from it was compared. Proflavine was bound very rapidly and more was bound at 0 °C than at 37 °C. Boiling increased the proflavine-binding capacity at 37 °C of sensitive but not of resistant cells. The binding capacity of sensitive and resistant cells suspended in buffer was the same; this was also true in various growth media. If cells were able to grow in the presence of proflavine their proflavine content decreased.Bound proflavine was released when cells were treated with growth media or with the salts of growth media. Sodium salts of organic acids also caused a release. This effect seemed due to their Na+ content, and was somewhat higher for resistant than for sensitive cells. The mechanism of proflavine resistance in B. subtilis is probably different from that of Escherichia coli, which is thought to depend on an energy-driven release of bound proflavine.

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