Solubility in blood, oxygen

Victims of carbon monoxide poisoning are placed in a hyperbaric chamber where the pressure is raised above 1 atm and a richer oxygen environment exists. If the pressure is raised from 1 atm to 3 atm, what will be the proportional change in oxygen solubility in blood Use Henry s law and assume blood behaves like water. 

Deep-sea divers breathe compressed air. Nitrogen is not very soluble in blood at normal pressures but at great depths, when the divers bodies are exposed to very high pressures, the nitrogen becomes more soluble. The dissolved nitrogen comes out of solution rapidly when the divers return to the surface, and numerous small bubbles form in the bloodstream. These bubbles can burst the capillaries—the narrow vessels that distribute the blood—or block them and starve the tissues of oxygen... 

Oxygen is much more readily soluble in blood than in water 100 c.c. of average human blood is able, when fully saturated in contact with air, to hold between 18 and 19 c.e. of oxygen measured at N.T.P. (see p. 135). In ethyl alcohol, oxygen is several times more soluble than in water.1 Its solubility at any temperature may be calculated from the following equation 2... 

Pressure affects the solubility of gaseous solutes and gaseous solutions. The solubility of a solute also depends on the nature of the solute and solvent. Temperature affects the solubility of all substances. To learn how a blood disorder called sickle-cell disease can affect oxygen s solubility in blood, read the Chemistry and Society feature at the end of this chapter. 

However, its solubility in blood is dramatically greater because of the high content of hemoglobin (Hb) molecules. Each hemoglobin molecule can bind up to four oxygen molecules, which are evenmaUy delivered to the tissues for use in metabolism ... 

This thermodynamic coupling between oxygen and carbon dioxide exhibited in water will also occur between any two gases in any solvent. A physiological example of this is the solubility of oxygen and carbon dioxide in blood, where it is found that increasing the partial pressure of Oo at fixed CO2 partial pressure results in an increased oxygen concentration in blood and decreased carbon dioxide concentration. Also, the situation is reversed if the CO2 partial pressure is increased at fixed O2 partial pressure. This phenomenon was first experimentally observed in 1914 and is referred to as the Bohr effect. 

In some cases, the small amount of a nonpolar gas that does dissolve is essential to a process. The most important environmental example is the solubility of O2 in water. At 25°C and 1 atm, the solubility of O2 is only 3.2 mL/100. mL of water, but aquatic animal life would die without this small amount. In other cases, the solubility of a gas may seem high because the gas is not only dissolving but also reacting with the solvent or another component. Oxygen seems much more soluble in blood than in water because O2 molecules are continually bonding with... 

Helium is extracted from some natural gas sources that contain up to 10% helium by volume. It has many uses that depend upon its unique properties. Because of its very low density compared with air, helium is used to fiU weather balloons and airships. Helium is nontoxic, odorless, tasteless, and colorless. Because of these properties and its low solubility in blood, helium is mixed with oxygen for breathing by deep sea divers and persons with some respiratory ailments. Use of helium by divers avoids the very painful condition called the bends caused by bubbles of nitrogen forming from nitrogen gas dissolved in blood. 

Thus, molecular oxygen is highly soluble in blood because it binds to hemoglobin. 

Fortius reason, some deep diving involves breathing a helium/oxygen mix. Helium does not form bubbles in the blood (it is less soluble in blood). 

An 80% helium, 20% oxygen mixture is used as an artificial atmosphere for divers. Nitrogen cannot be used because it is more soluble in the blood. When a diver starts to ascend, the nitrogen escapes from the blood too slowly, causing the bends, which can be fatal. Helium is less soluble in blood and so minimizes this problem. 

Another consequence of the effect of pressure on gas solubility is the painful, sometimes fatal, affliction known as the bends. This occurs when a person goes rapidly from deep water (high pressure) to the surface (lower pressure), where gases are less soluble. The rapid decompression causes air, dissolved in blood and other body fluids, to bubble out of solution. These bubbles impair blood circulation and affect nerve impulses. To minimize these effects, deep-sea divers and aquanauts breathe a helium-oxygen mixture rather than compressed air (nitrogen-oxygen). Helium is only about one-third as soluble as nitrogen, and hence much less gas comes out of solution on decompression. 

Divers avoid the bends by returning to the surface slowly, taking short decompression stops at intermediate depths to allow excess gas to escape from their blood without forming bubbles. Another way divers reduce the risk of the bends is by using helium-oxygen gas mixtures instead of compressed air. Helium is only half as soluble in water as nitrogen is, so less gas dissolves in blood. 

Trityl sodium is an extremely strong base, being soluble in ethers and aromatic hydrocarbons to give deep blood-red solutions so that in titration of an acid it can serve as its own visual indicator, although potentiometric detection is also possible a disadvantage is its high sensitivity to oxygen and moisture. 

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