scholarly journals ELECTRIFICATION OF WATER AND OSMOTIC PRESSURE

1919 ◽  
Vol 2 (1) ◽  
pp. 87-106 ◽  
Author(s):  
Jacques Loeb
Keyword(s):  
Osmotic Pressure ◽  
Salt Water ◽  
Pure Water ◽  
Preceding Paper ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
Positively Charged ◽  
As If ◽  
Charged Water

1. Amphoteric electrolytes form salts with both acids and alkalies. It is shown for two amphoteric electrolytes, Al(OH)3 and gelatin, that in the presence of an acid salt water diffuses through a collodion membrane into a solution of these substances as if its particles were negatively charged, while water diffuses into solutions of these electrolytes, when they exist as monovalent or bivalent metal salts, as if the particles of water were positively charged. The turning point for the sign of the electrification of water seems to be near or to coincide with the isoelectric point of these two ampholytes which is a hydrogen ion concentration of about 2 x 10–5 N for gelatin and about 10–7 for Al(OH)3. 2. In conformity with the rules given in a preceding paper the apparently positively charged water diffuses with less rapidity through a collodion membrane into a solution of Ca and Ba gelatinate than into a solution of Li, Na, K, or NH4 gelatinate of the same concentration of gelatin and of hydrogen ions. Apparently negatively charged water diffuses also with less rapidity through a collodion membrane into a solution of gelatin sulfate than into a solution of gelatin chloride or nitrate of the same concentration of gelatin and of hydrogen ions. 3. If we define osmotic pressure as that additional pressure upon the solution required to cause as many molecules of water to diffuse from solution to the pure water as diffuse simultaneously in the opposite direction through the membrane, it follows that the osmotic pressure cannot depend only on the concentration of the solute but must depend also on the electrostatic effects of the ions present and that the influence of ions on the osmotic pressure must be the same as that on the initial velocity of diffusion. This assumption was put to a test in experiments with gelatin salts for which a collodion membrane is strictly semipermeable and the tests confirmed the expectation.

scholarly journals CATAPHORETIC CHARGES OF COLLODION PARTICLES AND ANOMALOUS OSMOSIS THROUGH COLLODION MEMBRANES FREE FROM PROTEIN

1922 ◽  
Vol 5 (1) ◽  
pp. 89-107 ◽  
Author(s):  
Jacques Loeb
Keyword(s):  
Salt Solution ◽  
Electrical Transport ◽  
Pure Water ◽  
Diffusion Potential ◽  
Ion Concentration ◽  
High Concentration ◽  
Hydrogen Ion Concentration ◽  
Osmotic Effect ◽  
Diffusion Potentials ◽  
As If

1. It had been shown in previous papers that when a salt solution is separated from pure water by a collodion membrane, water diffuses through the membrane as if it were positively charged and as if it were attracted by the anion of the salt in solution and repelled by the cation with a force increasing with the valency. In this paper, measurements of the P.D. across the membrane (E) are given, showing that when an electrical effect is added to the purely osmotic effect of the salt solution in the transport of water from the side of pure water to the solution, the latter possesses a considerable negative charge which increases with increasing valency of the anion of the salt and diminishes with increasing valency of the cation. It is also shown that a similar valency effect exists in the diffusion potentials between salt solutions and pure water without the interposition of a membrane. 2. This makes it probable that the driving force for the electrical transport of water from the side of pure water into solution is primarily a diffusion potential. 3. It is shown that the hydrogen ion concentration of the solution affects the transport curves and the diffusion potentials in a similar way. 4. It is shown, however, that the diffusion potential without interposition of the membrane differs in a definite sense from the P.D. across the membrane and that therefore the P.D. across the membrane (E) is a modified diffusion potential. 5. Measurements of the P.D. between collodion particles and aqueous solutions (ϵ) were made by the method of cataphoresis, which prove that water in contact with collodion particles free from protein practically always assumes a positive charge (except in the presence of salts with trivalent and probably tetravalent cations of a sufficiently high concentration). 6. It is shown that an electrical transport of water from the side of water into the solution is always superposed upon the osmotic transport when the sign of charge of the solution in the potential across the membrane (E) is opposite to that of the water in the P.D. between collodion particle and water (ϵ); supporting the theoretical deductions made by Bartell. 7. It is shown that the product of the P.D. across the membrane (E) into the cataphoretic P.D. between collodion particles and aqueous solution (ϵ) accounts in general semiquantitatively for that part of the transport of water into the solution which is due to the electrical forces responsible for anomalous osmosis.

Ionic Equilibria and pH

2009 ◽  
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Pure Water ◽  
Weak Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
M 10 ◽  
Ionic Equilibria ◽  
Hydrated Protons ◽  
Dilute Aqueous Solution

Water is a weak acid. At 25°C, pure water ionizes to form a hydrogen ion and a hydroxide ion: H2O ⇋ H+ + OH− Hydration of the proton (hydrogen ion) to form hydroxonium ion is ignored here for simplicity. This equilibrium lies mainly to the left; that is, the ionization happens only to a slight extent. We know that 1 L of pure water contains 55.6 mol. Of this, only 10−7 mol actually ionizes into equal amounts of [H+] and [OH−], i.e., [H+] = [OH−] = 10−7M Because these concentrations are equal, pure water is neither acidic nor basic. A solution is acidic if it contains more hydrogen ions than hydroxide ions. Similarly, a solution is basic if it contains more hydroxide ions than hydrogen ions. Acidity is defined as the concentration of hydrated protons (hydrogen ions); basicity is the concentration of hydroxide ions. Pure water ionizes at 25°C to produce 10−7 M of [H+] and 10−7 M of [OH−]. The product Kw = [H+]×[OH−] = 10−7 M×10−7 M= 10−14 M is known as the ionic product of water. Note that this is simply the equilibrium expression for the dissociation of water. This equation holds for any dilute aqueous solution of acid, base, and salt. The pH of a solution is defined as the negative logarithm of the molar concentration of hydrogen ions. The lower the pH, the greater the acidity of the solution. Mathematically: pH=−log10[ H+] or −log10[H3O+] This can also be written as: pH = log10 1/[H+] or log10 1/[H3O+] Taking the antilogarithm of both sides and rearranging gives: [H+] = 10−pH This equation can be used to calculate the hydrogen ion concentration when the pH of the solution is known.

scholarly journals Spectrometric determinations of the effect of a neutral salt on the dissociation of acetic acid

1930 ◽  
Vol 130 (812) ◽  
pp. 1-16
Keyword(s):  
Acetic Acid ◽  
Methyl Orange ◽  
Preceding Paper ◽  
Ion Concentration ◽  
Neutral Salt ◽  
Apparent Dissociation Constant ◽  
Hydrogen Ion Concentration ◽  
K Value ◽  
Degree Of Dissociation ◽  
Colour Measurements

This paper gives an account of an extension of the work contained in the preceding paper (Sidgwick, Worboys and Woodward). For the first part the simple photoelectric colorimeter described in that paper was used. For the Second part a new type of flicker photometer was constructed. The principle of both instruments is the same, and has been given in the previous paper together with the theory of the colour changes of methyl orange, the indicator used throughout. The colour measurements allow us to determine the value of the apparent dissociation constant K of methyl orange in presence of various concentrations of natural salt. At a given salt concentration therefore the use of the appropriate K value will enable us to calculate the true hydrogen ion concentration of such a solution from its colour. In this way the degree of dissociation of acetic acid has been investigated in presence of different amounts of the neutral salt potassium bromide.

scholarly journals The Hydrogen Ion Concentration in the Gut of certain Lamellibranchs and Gastropods

1925 ◽  
Vol 13 (4) ◽  
pp. 938-952 ◽  
Author(s):  
O. M. Yonge
Keyword(s):  
Mantle Cavity ◽  
Mya Arenaria ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Pecten Maximus ◽  
Hydrogen Ions ◽  
Acid Media ◽  
Hydrogen Ion Concentration ◽  
Acid Reaction ◽  
Acid Region

1. In the Lamellibranchs, as typified by Pecten maximus, Mya arenaria and Ensis siliqua, the entire, gut has an acid reaction, the stomach being the most acid region and the pH rising along the mid-gut and rectum.2. The origin of the acidity of the gut lies in the style. This has a low pH (5·4 in Pecten and Mytilus, 4·6 in Ensis and 4·45 in Mya), and, after it has been artificially extracted from Mya or induced to disappear, by keeping the animals under abnormal conditions, in Mytilus, Tapes and Pecten, the pH of the stomach invariably rises (by as much as 0·825 in Mya and 0·72 in Tapes), although the pH in the mantle cavity has fallen.3. The style, which dissolves rapidly in alkaline or weakly acid media, is not dissolved in fluids below a certain pH—4·4 for Ensis, 4·2 for Mya, 3·6 for Pecten and Mytilus.4. The style is never absent, even though animals are starved, so long as they are kept under otherwise healthy conditions. The disappearance of the style under abnormal conditions is probably due to a lowering of the vital activities, which include the secretion of the style substance, and the consequent dissolution of the style by the less acid contents of the stomach.5. The style is only maintained as a result of a balance between the rate of its secretion and the rate of its dissolution.6. There is a well-marked correlation between the tolerance of the presence of hydrogen ions possessed by the cilia from the various regions of the gut and the degree of acidity of the fluid with which they are normally surrounded.7. The pH of the gut in five Gastropods has been investigated. The fore-gut and stomach have invariably the lowest pH.8. This acidity may be caused by the salivary glands (Patella and Buccinum), the digestive gland (Doris and Aplysia), or the style (Crepidula).9. The mid-gut and rectum have a high pH, except in Doris, where there is little secretion of mucus, the gut being free and muscular.10. The style of Orepidula has similar properties to those of the Lamellibranchs. It has a pH of 5·8, and is not dissolved in fluid of pH 3·6 or lower.11. The cilia from the gut of Buccinum and Doris can function in a pH of 5·0, but there is little difference in the toleration of the various cilia to the presence of hydrogen ions.

Proton semiconductors and energy transduction in biological systems

1978 ◽  
Vol 235 (3) ◽  
pp. R99-R114 ◽  
Author(s):  
H. J. Morowitz
Keyword(s):  
Proton Transport ◽  
Hydrogen Transfer ◽  
Atp Synthesis ◽  
Present Theory ◽  
Energy Transduction ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Detailed Model ◽  
Hydrogen Ion Concentration

Energy transduction processes in biology are analyzed in terms of ordered chains of hydrogen bonds. The theory is an extension of studies on proton conductance in ice and is stimulated by current ideas on the role of hydrogen ions in oxidative phosphorylation and photophosphorylation. The possibility of a protochemistry paralleling electrochemistry is presented along with experimental evidence. The theory relating transmembrane electrochemical potential difference of hydrogen ion concentration to the synthesis of ATP is reviewed. The thermodynamics of hydrogen transfer across a membrane is treated including electrochemical and electromechanical factors. As a prelude to considering ATP synthesis, the acid-base dissociation reactions of ATP, ADP, and phosphate are analyzed. The thermodynamics of ATP synthesis is discussed and a detailed model is presented coupling the synthesis to proton transport. The model assumes a gated proton semiconductor that carries protons and allows them to interact specifically with well-defined substrate molecules. The physics of proton transport is outlined and various methods examined in the context of biological membranes. Emphasis is placed on solid-state proton semiconductors and the present theory of such structures is given. A section is included on possible biological applications of these semiconductors.

Memoirs: The Spermatheca of Loligo Vulgaris. I. Structure of the Spermatheca and Function of its Unicellular Glands

1938 ◽  
Vol s2-80 (320) ◽  
pp. 593-599
Author(s):  
G. J. van OORDT
Keyword(s):  
Sea Water ◽  
Goblet Cells ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
Loligo Vulgaris ◽  
And Function

The structure of the spermatheca of Loligo vulgaris is described; it lies on the inner wall of the buccal membrane and within it large quantities of inactive spermatozoa are stored. This inactivity of the spermatozoa within the spermatheea is attributed to the effect of the secretion of the goblet-cells, situated as unicellular glands on the inner wall of the spermatheca. Inactive spermatozoa from the spermatheca become very active in sea-water, but are immobilized again after a few moments' contact with the pulp of the spermatheca contents. The hydrogen-ion concentration of the spermatheca contents is approximately 6.06; and, since spermatozoa become inactive in sea-water, the hydrogen-ion concentration of which is increased to this level, it seems probable that the inactivity of the spermatozoa within the spermatheca is due to the presence of hydrogen-ions. The spermatheca is functionally comparable to the mammalian epididymis.

Surface Forces in the Tracheal System of Insects

1953 ◽  
Vol s3-94 (28) ◽  
pp. 507-522
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Salt Water ◽  
Swelling Pressure ◽  
Secretory Activity ◽  
Ion Concentration ◽  
Mosquito Larvae ◽  
Tracheal System ◽  
Hydrogen Ion Concentration ◽  
A Cell ◽  
Physical Forces ◽  
Anal Papillae

The mechanism by which the tracheal system becomes filled with air is reviewed. It is concluded that the fluid contents are actively absorbed by the walls of the system. The air often enters from the atmosphere through the spiracles. In some insects the system fills while the insect is submerged in water or while the spiracles are closed. It is shown by means of simple models how the tanning of the lining of the larger tracheae or the secretion of wax over the walls will bring about the liberation of gas from solution when the fluid is subjected to a very slight negative pressure. The movements of fluid in the tracheole endings of insects are also reviewed. The removal of fluid which takes place during activity, particularly under conditions of deficient oxygen supply, is not caused by secretory activity but by the physical forces produced by the products of metabolism. The evidence supports the view that the fluid in the tracheoles is a cell sap whose passage up the tracheole under the action of capillarity is opposed by the elasticity or swelling pressure of the cytoplasmic sheath of the tracheoles. It is shown by means of a simple gelatin model how osmotic changes in the surrounding fluid, acting by way of a cytoplasmic sheath, will bring about the absorption of such a cell sap. A more exact model, illustrating the greater permeability of the inner wall of the tracheole which the proposed mechanism requires, is provided by the anal papillae of mosquito larvae. These structures show the same adaptation to a saline medium as is postulated in the tracheoles of mosquito larvae from salt water. Alternative mechanisms are discussed. It is suggested that the capillary forces in the tracheoles are probably small. The effects of probable contamination of the tracheole fluid by an oily film (Beament) and the effects of changes in hydrogen-ion concentration on interfacial tensions are illustrated by reference to further models.

A physiological approach to acid–base disorders: The roles of ion transport and body fluid compartments

2020 ◽  
pp. 2182-2198
Author(s):  
Julian Seifter
Keyword(s):  
Metabolic Acidosis ◽  
Gas Analysis ◽  
Hydrogen Ion ◽  
Anion Gap ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Arterial Blood Gas ◽  
Fluid Compartments

The normal pH of human extracellular fluid is maintained within the range of 7.35 to 7.45. The four main types of acid–base disorders can be defined by the relationship between the three variables, pH, Pco2, and HCO3 –. Respiratory disturbances begin with an increase or decrease in pulmonary carbon dioxide clearance which—through a shift in the equilibrium between CO2, H2O, and HCO3 –—favours a decreased hydrogen ion concentration (respiratory alkalosis) or an increased hydrogen ion concentration (respiratory acidosis) respectively. Metabolic acidosis may result when hydrogen ions are added with a nonbicarbonate anion, A−, in the form of HA, in which case bicarbonate is consumed, or when bicarbonate is removed as the sodium or potassium salt, increasing hydrogen ion concentration. Metabolic alkalosis is caused by removal of hydrogen ions or addition of bicarbonate. Laboratory tests usually performed in pursuit of diagnosis, aside from arterial blood gas analysis, include a basic metabolic profile with electrolytes (sodium, potassium, chloride, bicarbonate), blood urea nitrogen, and creatinine. Calculation of the serum anion gap, which is determined by subtracting the sum of chloride and bicarbonate from the serum sodium concentration, is useful. The normal value is 10 to 12 mEq/litre. An elevated value is diagnostic of metabolic acidosis, helpful in the differential diagnosis of the specific metabolic acidosis, and useful in determining the presence of a mixed metabolic disturbance. Acid–base disorders can be associated with (1) transport processes across epithelial cells lining transcellular spaces in the kidney, gastrointestinal tract, and skin; (2) transport of acid anions from intracellular to extracellular spaces—anion gap acidosis; and (3) intake.

scholarly journals SOME CONSEQUENCES OF THE THEORY OF MEMBRANE EQUILIBRIA

1925 ◽  
Vol 9 (1) ◽  
pp. 97-109 ◽  
Author(s):  
David I. Hitchcock
Keyword(s):  
Membrane Potential ◽  
Osmotic Pressure ◽  
Ionization Constant ◽  
Weak Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Weak Base ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Pass Through

In applying Donnan's theory of membrane equilibria to systems where the non-diffusible ion is furnished by a weak acid, base, or ampholyte, certain new relations have been derived. Equations have been deduced which give the ion ratio and the apparent osmotic pressure as functions of the concentration and ionization constant of the weak electrolyte, and of the hydrogen ion concentration in its solution. The conditions for maximum values of these two properties have been formulated. It is pointed out that the progressive addition of acid to a system containing a non-diffusible weak base should not cause the value of the membrane potential to rise, pass through a maximum, and fall, but should only cause it to diminish. It is shown that the theory predicts slight differences in the effect of salts on the ion ratio in such systems, the effect increasing with the valence of the cation.

Cadmium in the aquatic environment: a review of ecological, physiological, and toxicological effects on biota

1994 ◽  
Vol 2 (2) ◽  
pp. 187-214 ◽  
Author(s):  
D. A. Wright ◽  
P. M. Welbourn
Keyword(s):  
Metal Binding ◽  
Chronic Toxicity ◽  
Field Experiments ◽  
Salt Water ◽  
Global Scale ◽  
Ion Concentration ◽  
Toxicity Tests ◽  
Aquatic Biota ◽  
Cadmium Ion ◽  
Hydrogen Ion Concentration

Cadmium is a nonessential element that can be toxic and carcinogenic. On a global scale, the ratio anthropogenic to natural emissions of cadmium is approximately 7:1. Sources of cadmium for freshwater and salt water include atmospheric deposition, direct and via runoff, as well as direct discharges into water or watersheds. Thirty percent of the atmospheric emissions fall onto water. In freshwater, the cadmium ion is the predominant dissolved form, while in seawater, chloride dominates. Much of the cadmium added to aquatic systems accumulates in sediments where it presents a risk to benthic biota and under certain conditions may reenter the water column. The cadmium ion is the most bioavailable to aquatic biota; factors affecting availability include salinity, dissolved organic matter, and hydrogen ion concentration, which affect the chemical forms of cadmium. Hydrogen and other ions, most notably calcium, also affect cadmium uptake and toxicity, through competition and physiological effects. The concentrations of cadmium that result in acute or chronic toxicity vary over several orders of magnitude, with certain freshwater fish and invertebrates being the most sensitive. Long-term field experiments and chronic toxicity tests on invertebrates suggest that the present Canadian guideline of 200 ng Cd∙L−1 for the protection of freshwater biota may be too high. Aquatic animals and plants, like most organisms, produce metal binding proteins, called metallothioneins, in response to cadmium. Some species or varieties within a species of aquatic biota are tolerant to cadmium. The relationship between cadmium tolerance and metallothionein is still incompletely resolved.Key words: cadmium, seawater, freshwater, availability, toxicity, metallothionein, tolerance, food chain.

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