Gas laws in anesthesia
ANES 5101
Assignment 2
Name: ______________________________________ Due date:
1. Calculate the root mean square velocity and kinetic energy of CO, CO2, and SO3 at 298 K.
Which gas has the greatest velocity? __________
The greatest kinetic energy? __________
The greatest effusion rate? __________
2. We separate U-235 from U-238 by fluorinating a sample of uranium to form UF6 (which is a gas) and then taking advantage of the different rates of effusion and diffusion for compounds containing the two isotopes. Calculate the ratio of effusion rates for 238UF6 and 235UF6. The atomic mass of U-235 is 235.054 amu and that of U-238 is 238.051 amu.
3. Calculate the ratio of effusion rates for Ar and Kr.
4. A sample of neon effuses from a container in 76 seconds. The same amount of an unknown noble gas requires 155 seconds. Identify the second gas.
5. A sample of N2O effuses from a container in 42 seconds. How long will it take the same amount of gaseous I2 to effuse from the same container under identical conditions?
6. Using the data shown in Table 5.5, calculate the pressure exerted by 4.37 moles of molecular chlorine confined in a volume of 2.45 L at 38°C. Compare the pressure with that calculated using the ideal gas equation.
7. Potassium superoxide (KO2) is a useful source of oxygen employed in breathing equipment. Exhaled air contains moisture, which reacts with KO2 to produce oxygen gas. (The other products are potassium hydroxide and hydrogen peroxide.)
a) Write an equation for the reaction.
b) Calculate the pressure at which oxygen gas stored at 20°C would have the same density as the oxygen gas provided by KO2 . The density of KO2 at 20°C is 2.15 g/cm3
8. The barrel of a syringe has a diameter of 1.0 cm, while the diameter of the needle is 0.020 cm. If you apply a pressure on the plunger so that the medicine moves at 1.0 cm/s through the barrel, how fast does it move through the needle?
9. A Venturi tube is attached to an Entonox line. The manometer in the Venturi tube is filled with water and shows a pressure difference of 20 mmH2O. If the radii of the Venturi tube are 1.0 and 0.10 cm, what is the flow rate of the anesthetic gas? Assume the density of the Entonox is 1.9 kg/m3.
10. If water is moving at a speed of 0.15 m/s through a tube with a cross sectional area of 0.010 m2, what is the flow rate?
11. A sample of helium gas flows at a rate of 100 cm3/s through a tube having a radius of 0.500 cm. What is the speed of the He?
12. If the He from the previous question enters a tube having a radius of 0.0500 cm, what is the speed of the He?
13. Cyclopropane moves with a speed of 1.0 m/s through a tube of diameter 1.0 cm and enters a tube with a diameter of 0.010 cm. By how much does the speed increase and what is the pressure drop? The density of cyclopropane is 1.8 kg/m3.
14. What flow rate will a pressure of 20 Pa drive nitrous oxide through a 10m tube of radius 0.0010 m if the density of N2O is 2.0 kg/m3 and the viscosity is 1.8 × 10-5 Pa・s?
15. The solubility of N2 in blood at 37°C and at a partial pressure of 0.80 atm is 5.6 x 1024 mol/L. A deepsea diver breathes compressed air with the partial pressure of N2 equal to 4.0 atm. Assume that the total volume of blood in the body is 5.0 L. Calculate the amount of N2 gas released (in liters at 37°C and 1 atm) when the diver returns to the surface of the water, where the partial pressure of N2 is 0.80 atm.
16. Air entering the lungs ends up in tiny sacs called alveoli. It is from the alveoli that oxygen diffuses into the blood. The average radius of the alveoli is 0.0050 cm and the air inside contains 14 percent oxygen. Assuming that the pressure in the alveoli is 1.0 atm and the temperature is 37°C, calculate the number of oxygen molecules in one of the alveoli. ( Hint: The volume of a sphere of radius r is 4/3 Πr3.)
17. A certain anesthetic contains 64.9 percent C, 13.5 percent H, and 21.6 percent O by mass. At 120°C and 750 mmHg, 1.00 L of the gaseous compound weighs 2.30 g. What is the molecular formula of the compound?
18. A student carried out the following procedure to measure the pressure of carbon dioxide in a soft drink bottle. First, she weighed the bottle (853.5 g). Next, she carefully removed the cap to let the CO2 gas escape. She then reweighed the bottle with the cap (851.3 g). Finally, she measured the volume of the soft drink (452.4 mL). Given that Henry’s law constant for CO2 in water at 25°C is 3.4 x 1022 mol/L atm, calculate the pressure of CO2 in the original bottle.
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