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Hyperbaric oxygenation therapy involves placing a patient in a chamber with oxygen-rich air at greater than atmospheric pressure. Normal air has approximately 78% N 2 , 21% O 2 , and trace amounts of other gases. The pressure within the hyperbaric chamber is typically measured in terms of ATA, or atmospheres absolute (1 ATA is the average atmospheric pressure at sea level, or 1 atm). A hyperbaric chamber set at 2.5 ATA would be the average atmospheric pressure at sea level (1 ATA) plus the additional pressure applied to the chamber (1.5 ATA).There are two main types of hyperbaric chambers: monoplace chambers and multiplace chambers. Monoplace chambers accommodate a single person. The air in these chambers is 100% oxygen and can be raised to a maximum pressure of 3 ATA. Monoplace chambers are used as therapy for conditions where oxygen supply has been depleted, such as carbon monoxide poisoning. They are also used when a higher concentration of oxygen in plasma is needed, such as in wound healing.Multiplace chambers are large enough to house at least four people. The air in these chambers is typically a mixture of oxygen and nitrogen, but the patient breathes pure oxygen through a mask. Some multiplace chambers can endure maximum pressures of 6 ATA and are typically used to eliminate intravascular air bubbles that can occur from decompression sickness or embolisms. The high pressure from the multiplace chamber results in a decrease in volume of any air pockets within the body, including the sinuses, inner ear, and unwanted air bubbles in the arteries or veins.Patients report that their ears "pop" during the pressurization process, similar to being on an airplane in flight. In addition, they report that although there is an initial sense of temperature increasing, the chamber's temperature stays relatively stable during both the pressurization and the depressurization processes.
-The graph below shows how much certain real gases deviate from ideal behavior. If the ideal gas law is considered to give a close approximation for the behavior of a real gas that has a deviation of 1.0% or less, based on the graph, which of the following statements is true?

Question

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Hyperbaric oxygenation therapy involves placing a patient in a chamber with oxygen-rich air at greater than atmospheric pressure.  Normal air has approximately 78% N 2 , 21% O 2 , and trace amounts of other gases.  The pressure within the hyperbaric chamber is typically measured in terms of ATA, or atmospheres absolute (1 ATA is the average atmospheric pressure at sea level, or 1 atm).  A hyperbaric chamber set at 2.5 ATA would be the average atmospheric pressure at sea level (1 ATA) plus the additional pressure applied to the chamber (1.5 ATA).There are two main types of hyperbaric chambers: monoplace chambers and multiplace chambers.  Monoplace chambers accommodate a single person.  The air in these chambers is 100% oxygen and can be raised to a maximum pressure of 3 ATA.  Monoplace chambers are used as therapy for conditions where oxygen supply has been depleted, such as carbon monoxide poisoning.  They are also used when a higher concentration of oxygen in plasma is needed, such as in wound healing.Multiplace chambers are large enough to house at least four people.  The air in these chambers is typically a mixture of oxygen and nitrogen, but the patient breathes pure oxygen through a mask.  Some multiplace chambers can endure maximum pressures of 6 ATA and are typically used to eliminate intravascular air bubbles that can occur from decompression sickness or embolisms.  The high pressure from the multiplace chamber results in a decrease in volume of any air pockets within the body, including the sinuses, inner ear, and unwanted air bubbles in the arteries or veins.Patients report that their ears "pop" during the pressurization process, similar to being on an airplane in flight.  In addition, they report that although there is an initial sense of temperature increasing, the chamber's temperature stays relatively stable during both the pressurization and the depressurization processes.
-The graph below shows how much certain real gases deviate from ideal behavior.  If the ideal gas law is considered to give a close approximation for the behavior of a real gas that has a deviation of 1.0% or less, based on the graph, which of the following statements is true?

Quizplus · Accepted Answer

11ecba2d_1206_e8fb_a3bf_f3f2eee54870_MD0008_00 Two of the assumptions made by the ideal gas law are that the volume of the individual particles of gas is negligible, and the individual particles of gas do not interact with each other. These assumptions are adequate for most gases at low pressure. However, at higher pressures the individual particles are closer together, resulting in an increased gas density. An increased density results in a greater likelihood that the gas particles will interact with each other in a nonelastic way. Furthermore, at extremely high pressures, the combined molecular volume occupied by the gas particles becomes significant relative to the volume of the container. These factors lead to deviations from ideal behavior in real gases. To experimentally determine how much a particular gas deviates from ideal behavior, a graph of PV/nRT vs. P can be prepared. Real gases with perfectly ideal behavior should exhibit a constant ratio of PV/nRT equal to 1 because the ideal gas equation states that PV = nRT. Carbon dioxide deviates significantly (>1.0%) from ideal behavior at pressures above 2 atm. Oxygen and nitrogen deviate significantly at higher pressures (>8 atm). Therefore, at pressures between 2 and 4 atm, the ideal gas law gives a close approximation for the behavior of nitrogen and oxygen but does not give a close approximation for the behavior of carbon dioxide. (Choice B) Atmospheric pressure is defined as 1 atm at standard conditions. Based on the graph, at 1 atm the ideal gas law gives a close approximation for the behavior of all three gases. (Choice C) At pressures below 4.0 atm, the trend lines for the gases show that O₂ has a much lower deviation than CO₂ but a slightly higher deviation than N₂. Therefore, O₂ behaves more like an ideal gas than CO₂, but not more so than N₂. (Choice D) Above 4.0 atm, CO₂ deviates more than 1.0% from ideal behavior; therefore, the ideal gas law does not give a close approximation for the behavior of CO₂ above 4.0 atm. Educational objective: At higher pressures, deviations from ideal gas behavior occur because the density of a gas increases enough that the individual gas particles are more likely to interact in a nonelastic way, and the molecular volume occupied by the gas particles becomes significant relative to the volume of the container.