1. chemistry

    to reduce loss of helium , a pressure vessel is lined with a membrane made of tantalum.the concentrate of helium at the inner surface of the membrane is held constant at 4.44*10^-5kg/cm3, which the concentrate at the outer surface of the membrane is held
  2. chemistry

    To reduce the loss of helium, a pressure vessel is lined with a membrane made of tantalum. The concentration of helium at the inner surface of the membrane is held constant at 4.44*10-5 kg/m3, while the concentration at the outer surface of the membrane is
  3. chemistry

    A pressure vessel is lined with a membrane to reduce the loss of helium. The membrane is made of a material through which the diffusivity of helium at 25 C is 3.091 x 10-10 m2/s. The concentration at the inner surface is maintained constant at 4.00 x 10-6
  4. Physics

    The membrane that surrounds a certain type of living cell has a surface area of 2.13 x 10-9 m2 and a thickness of 1.94 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 6.4. (a) If the potential on
  5. physics

    The membrane that surrounds a certain type of living cell has a surface area of 4.9 x 10-9 m2 and a thickness of 1.2 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.5. (a) The potential on the
  6. physics

    The membrane that surrounds a certain type of living cell has a surface area of 4.4 x 10-9 m2 and a thickness of 1.6 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 4.1. (a) The potential on the
  7. physics

    The membrane that surrounds a certain type of living cell has a surface area of 4.50 × 10-9 m2 and a thickness of 1.00 × 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.3. The potential on the
  8. biology

    A toxin from a poisonous mushroom has been identified as a hydrophobic weak acid. It somehow can find its way to the inner membrane of mitochondria where it gets protonated on the outer surface of the membrane but deprotonated on the inner surface of the
  9. physics

    An axon is the relatively long tail-like part of a neuron, or nerve cell. The outer surface of the axon membrane is charged positively, and the inner surface is charged negatively. The membrane itself has a dielectric constant k ~ 5 and a thickness d ~
  10. biology

    A toxin from a poisonous mushroom has been identified as a hydrophobic weak acid. It somehow can find its way to the inner membrane of mitochondria where it gets protonated on the outer surface of the membrane but deprotonated on the inner surface of the
  11. physics 2

    The inner and outer surface of a cell membrane carry a negative and a positive charge, respectively. Because of these charges, a potential difference of about 0.070 V exists across the membrane. The thickness of the cell membrane is 8.0 × 10−9m.
  12. Chemistry

    A vessel containing 39.5 cm3 of helium gas at 25°C and 106 kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of helium. If this required 17.8 cm3 of ethanol, what was the
  13. Chemistry

    A vessel containing 39.5 cm3 of helium gas at 25°C and 106 kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of helium. If this required 17.8 cm3 of ethanol, what was the
  14. Chemistry

    A vessel containing 39.5 cm3 of helium gas at 25°C and 106 kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of helium. If this required 18.8 cm3 of ethanol, what was the
  15. Physiscs 222

    The inner and outer surfaces of a cell membrane carry a negative and positive charge respectively. Because of these charges, a potential difference of about 70*10-3 V exists across the membrane. The thickness of the membrane is 8.0*10-9 m. Assumption the
  16. Physics

    The membrane that surrounds a certain type of living cell has a surface area of 4.50 10-9 m2 and a thickness of 1.08 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.40. If the charge in part (a)
  17. AP Chemistry

    Three gases, xenon, helium, and hydrogen are confined in a 10.0 L vessel at a pressure of 7.0 atm. Intially the vessel contains 3.0 moles of xenon, 2.0 moles of helium, and 2.0 moles of hydrogen. What would the partial pressure of helium be if 5.0 moles of
  18. Physics

    A simplified model for an erythrocyte is a spherical capacitor with a positive inner surface of area A and a membrane of thickness b. Use potential difference of 98 mV across the membrane and a dielectric constant K = 5.0. If the capacitance of the
  19. Physics

    A simplified model for an erythrocyte is a spherical capacitor with a positive inner surface of area A and a membrane of thickness b. Use potential difference of 86 mV across the membrane and a dielectric constant K = 5.0. If the capacitance of the
  20. Biology

    Which statement is NOT true about the proteins in the plasma membrane? -Proteins may be attached to the inner surface of the plasma membrane. -The hydrophobic portion of a protein is embedded within the membrane. -Some peripheral proteins are connected to
  21. PHYSICS

    I'm having some trouble with a problem on my physics pre-exam, if there is any formula please let me know so i can do a bit of research on it. any help is greatly appreciated in advance. The inner membrane of a cell membrane is negative relative to the
  22. Physics

    The inner and outer surfaces of a cell membrane carry a negative and positive charge, respectively. Because of these charges, a potential difference of about 0.070 V exists across the membrane. The thickness of the membrane is 0.000000008 m. What is the
  23. victoria Ci

    We find an electric field of magnitude E = 1.2 x 107 V/m across a particular nerve membrane. The potential difference between the interior and exterior surface of the membrane is 65 mV. The thickness of the membrane is closest to
  24. Physics 112

    The inner and outer surfaces of a cell membrane carry a negative and a positive charge, respectively. Because of these charges, a potential difference of about 0.075 V exists across the membrane. The thickness of the cell membrane is 7.80 10-9 m. What is
  25. chem

    A vessel containing 39.5 cm^3 of helium gas at 25 degrees celsius and 106 kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of helium. If tihs required 7.7 cm^3 of ethanol,
  26. Chemistry

    A vessel containing 39.5 cm^3 of helium gas at 25°C and 106kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of helium. If this required 7.7cm^3 of ethanol, what was the
  27. English

    1. I can't concentrate on work. 2. I can't concentrate at work. 3. I can't concentrate (on something) at work. ------------------ Which one is correct? Does #1 mean #3? •English - Writeacher, Saturday, June 18, 2016 at 8:46am 1 and 2 are fine, but mean
  28. Microbiology

    Which of the following statements about the outer membrane of Gram-negative cell wall is FALSE? A. The outside leaflet is largely composed of lipopolysaccharides. B. The outer membrane contains porins that allow passage of molecules and ions directly into
  29. physics

    A potential difference of 102 mV exists between the inner and outer surfaces of a cell membrane. The inner surface is negative relative to the outer surface. How much work is required to eject a positive sodium ion (Na+) from the interior of the cell? (in
  30. physics

    The inner and outer surfaces of a cell membrane carry a negative and positive charge, respectively. Because of these charges, a potential difference of about 0.070 V exists across the membrane. The thickness of the membrane is 9.00*10-9 m. What is the
  31. chemistry

    A slab of plate glass containing dissolved helium is placed in a vacuum furnace at a temperature of 400 C to remove the helium from the glass. The concentration of helium is constant throughout the glass before vacuum heat treatment. After 10 minutes in
  32. Physics

    A simplified model for an erythrocyte is a spherical capacitor with a positive inner surface of area A and a membrane of thickness b. Use potential difference of 94 mV across the membrane and a dielectric constant K = 5.0. If the capacitance of the
  33. Physics

    A sealed container of volume 0.10 m3 holds a sample of 3.0 x 10^24 atoms of helium gas in equilibrium. The distribution of speeds of helium atoms shows a peak at 1100 ms-1. Caluculate the temperature and pressure of the helium gas. (helium atom 4.0 amu)
  34. chemistry

    Which statement correctly describes an atom of the element helium? A. An atom of helium has its valence electrons in it's first energy level. B. An atom of helium most similarly behaves like an atom of hydrogen since it is in the same period. C. An atom of
  35. General Chemistry

    A cylinder with a movable piston contains 2.00g of helium,He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the
  36. CHEM

    A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume
  37. Chemestry

    A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume
  38. chemistry

    A cylinder with a movable piston contains 2.00 g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the
  39. Chem

    Please tell me if these are right? A mixture of oxygen and helium is prepared for a scuba diver that will descend to 125 feet below the ocean surface. At that depth the diver breathes a gas mixture that has a total pressure of 8atm. If the particle
  40. Physics

    An unknown potential difference exists between the inner and outer surfaces of the membrane of a cell. The inner surface is negative relative to the outer surface. If 2.5 x 10-20 J of work is needed to eject a positive Calcium ion (Ca2+) from the interior
  41. Biology

    How can the mass transfer kc and ultrafiltration solvent flux be increased? Select one: a. Another stream of fluid can flow adjacent to the membrane to accumulate solute at the membrane surface b. Another stream of fluid can flow perpendicular to the
  42. Biology

    Hi, one more question to clarify: How can the mass transfer kc and ultrafiltration solvent flux be increased? Select one: a. Another stream of fluid can flow adjacent to the membrane to accumulate solute at the membrane surface b. Another stream of fluid
  43. college chemisrty

    A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume
  44. Physics

    A sealed container of volume V =0 .10m^3 holds a sample of N =3 .0×10^24 atoms of helium gas in equilibrium. The distribution of speeds of the helium atoms shows a peak at 1.1×10^3 ms^−1. (i) Calculate the temperature and pressure of the helium gas.
  45. Physics

    A clown at a birthday party has brought along a helium cylinder, with which he intends to fill balloons. When full, each balloon contains 0.00280 m3 of helium at an absolute pressure of 1.20 x 105 Pa. The cylinder contains helium at an absolute pressure of
  46. university physics

    A cryogenic storage container holds liquid helium, which boils at 4.20 K. Suppose a student painted the outer shell of the container black, turning it into a pseudo-blackbody, and that the shell has an effective area of 0.615 m2 and is at 3.01·102 K. a)
  47. Physic

    Please urgent help me A cryogenic storage container holds liquid helium, which boils at 4.20 K. Suppose a student painted the outer shell of the container black, turning it into a pseudo-blackbody, and that the shell has an effective area of 0.487 m2 and
  48. university physic

    A cryogenic storage container holds liquid helium, which boils at 4.20 K. Suppose a student painted the outer shell of the container black, turning it into a pseudo-blackbody, and that the shell has an effective area of 0.487 m2 and is at 3.01·102 K. a)
  49. chemistry

    A helium-filled balloon of the type used in long-distance flying contains 420,000 ft3 (1.2 times 107 L) of helium. Suppose you fill the balloon with helium on the ground, where the pressure is 737 mm Hg and the temperature is 16.0 °C. When the balloon
  50. physics

    A typical cell membrane is 8.0 nm thick and has an electrical resistivity of 1.3 × 107Ω.m. (i) If the potential difference between the inner and outer surfaces of a cell membrane is 75 mV, how much current flows through a square area of
  51. physics

    A typical cell membrane is 8.0 nm thick and has an electrical resistivity of 1.3 × 107Ω.m. (i) If the potential difference between the inner and outer surfaces of a cell membrane is 75 mV, how much current flows through a square area of
  52. Chemistry (Insulated Vessel, temperature and vol.)

    Insulated vessel has two compartments separated by a membrane. One side is 1 kg of steam at 400 C and 200 bar. The other side is evacuated. The membrane ruptures filling the entire volume. The final pressure is 100 bar. Determine the final temperature of
  53. college chemistry

    A sample of helium occupies 1521 mL at 719 mmHg. Assume that the temperature is held constant and determine a) the volume of the helium at mmHg. b)the pressure, in mmHg, if the volume is changed to 315mL
  54. physics

    Spaceman Spiff sits just outside the Milky Way galaxy with a cup of liquid Helium which is at approximately 4K (-269 0C). He has with him a small sphere made entirely of copper which is at a temperature of 219K (-54 0C). After a certain amount of time his
  55. Chemistry

    A sample of helium has a volume of 325mL and a pressure of 655mmHg. What wll be the pressure if the helium is compressed to 125mL (T constant)?
  56. chemistry

    A sample of helium has a volume of 235 ml and a pressure of 565 mm Hg. What will be the pressure if the helium is compressed to 215 mL (T constant)
  57. CHEm

    Amount of Helium in a Blimp The Goodyear blimp Spirit of Akron is 62.6 m long and contains 7023 m^3 of helium. When the temperature of the helium is 280K , its absolute pressure is 110kPa . Find the mass of the helium in the blimp. m=_____kg ty
  58. biology

    Why is a large surface area : volume ratio needed for cells to function properly? a.Adequate surface area (plasma membrane) is needed to furnish nutrients to and expel wastes from the volume (cytoplasm). b. Smaller volumes reduce and larger surface areas
  59. Chem

    Would you please tell me if these are right? A sample of helium has a volume of 325 ml and a pressure of 655 mm hg. What will be the pressure if the helium is compressed to 125 ml (t and n are constant) I got 1703 mm of Hg A 75.0 ml sample of oxygen has a
  60. chem

    A balloon filled with 22.3 mol helium has a volume of 500. L at 0.0°C and 1.00 atm pressure. The temperature of the balloon is increased to 38.0°C as it expands to a volume of 570. L, the pressure remaining constant. Calculate q, w, and E for the helium
  61. chem

    A balloon filled with 22.3 mol helium has a volume of 500. L at 0.0°C and 1.00 atm pressure. The temperature of the balloon is increased to 38.0°C as it expands to a volume of 570. L, the pressure remaining constant. Calculate q, w, and E for the helium
  62. Physics

    Three cylindrical blocks x, y and z are made of different materials of densities 2g/cm3, 5g/cm3 and 10g/cm3 respectively. If the side of each block resting on a level surface has an area of 2cm2, 4cm2 and 6cm2 and the height of block x is 10cm calculate;
  63. Chemistry

    Bill and Bob have been testing a new aluminised PET (Polyethylene Terephthalate) film and they now use the material to make helium filled balloons. Bill’s balloon is less inflated than Bob’s, and the latter jokes about it. However, Bill insists he has
  64. Chemistry

    Bill and Bob have been testing a new aluminised PET (Polyethylene Terephthalate) film and they now use the material to make helium filled balloons. Bill’s balloon is less inflated than Bob’s, and the latter jokes about it. However, Bill insists he has
  65. CHEM

    A cylinder with a movable piston contains 2.00g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the
  66. Chemistry

    A 334-mL cylinder for use in chemistry lectures contains 5.225 g of helium at 23 C. How many grams of helium must be releasedto reduce the pressure to 75 atm assuming ideal gas behavior?
  67. Chemistry

    You have a tank of helium with a volume of 10 liters that is currently under 40 atm of pressure. If you open the valve on the tank and release the helium into a room with a volume of 10,000 liters, how many atmospheres of pressure will the helium now be
  68. Physics plzzzzzzzzz help

    Ideal Gas Law: PV = N k T ---> N = PV/(k T) N = 1.387*10^(29) mass of one helium atom is approximately 4*u = 6.642*10^27 kg 4u*N = 921 kg A Goodyear blimp typically contains 4770 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The
  69. Physics

    We can physically model the axonal membrane (axolemma) as a parallel plate capacitor with dielectric in it. If the capacitance per unit area in F/m^2 is known, what single additional parameter needs to be measured in order to determine the dielectric
  70. Chemistry

    I need help with this question. 1. You have a tank of helium with a volume of 10 liters that is currently under 40 atm of pressure. If you open the valve on the tank and release the helium into a room with a volume of 10,000 liters, how many atmospheres of
  71. Math

    Mix W = 5 Cups Concentrate and 8 Cups Cold Water, Mix X = 3 cups concentrate 6 cups cold water, Mix Y = 6 Cups Concentrate 9 Cups cold water, Mix Z = 3 Cups Concentrate 5 cups cold water Question: If possible, write each comparison of concentrate to water
  72. 12th grade physics

    Helium is monatomic with a relative atomic mass of 4. calculate (i) the density of helium gas at a temperature of 0 degrees Celsius and a pressure of 101kPa and (ii) the rms speed of the helium atoms under these conditions
  73. chemistry

    A helium balloon contains 0.30g of helium. Given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?
  74. Chemistry

    A helium balloon contains 0.54g of helium. Given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?
  75. math

    A bottle of juice concentrate gives the mixing ratio of concentrate to water as 1:5. How much water should be mixed with 2 cups of concentrate?
  76. ccbc

    A 12.3 vessel was found to contain N2, Ar He, and He. The total pressure in the vessel was 987 torr and the partial pressures of nitrogen, argon, and helium were 44 torr, 486 torr, and 218 torr, respectively. What was the pressure of neon in the vessel?
  77. Chem

    A 12.3 vessel was found to contain N2, Ar He, and He. The total pressure in the vessel was 987 torr and the partial pressures of nitrogen, argon, and helium were 44 torr, 486 torr, and 218 torr, respectively. What was the pressure of neon in the vessel?
  78. physics

    A cryogenic storage container holds liquid helium, which boils at 4.20 K. Suppose a student painted the outer shell of the container black, turning it into a pseudo-blackbody, and that the shell has an effective area of 0.791 m2 and is at 2.95·102 K. What
  79. PHYSICS

    A Goodyear blimp typically contains 5040 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The temperature of the helium is 282 K. What is the mass (in kg) of the helium in the blimp?
  80. Physics

    The boiling point of helium at 1 atm is 4.2 K. What is the volume occupied by helium gas due to evaporation of 70 g of liquid helium at 1 atm pressure and a temperature of 6.2 K?
  81. Chemistry

    A helium ballon contains 0.32g of helium. Given the molecular weight of helium is 4. How many moles of helium does it contain.
  82. Chemistry

    A helium balloon contains 0.50 g of helium. Given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?
  83. Physics please help !

    A Goodyear blimp typically contains 4770 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The temperature of the helium is 274 K. What is the mass (in kg) of the helium in the blimp? You asked this twice. See my response to your later post.
  84. physics

    A Goodyear blimp typically contains 5400m^3 of helium (He) at an absolute pressure of 1.1*10^5Pa. The temperature of the helium is 280K. What is the mass (in kg)of the helium in the blimp? PLEASE GIVE ME SOME IDEAS TO DO IT!!!THANKS A LOT!!!
  85. Chemistry

    A rubber balloon was filled with helium at 25˚C and placed in a beaker of liquid nitrogen at -196˚C. The volume of the cold helium was 15 cm3 Assuming ideal gas behavior and isobaric conditions, what was the volume of the helium at 25˚C?
  86. Biochemistry

    A cell has a resting membrane potential of -66 mV and a membrane Cl ion equilibrium potential of -24.0 mV If a neurotransmitter acts on the cell membrane to open channels that are specifically permeable to Cl, will the membrane potential of the cells
  87. Bio/Science PLEASE HELP

    If the axo-membrane becomes more permeable to potassium ions.. Which onewould be true? A. the inside of the membrane will become more positively charged. B. the membrane will depolarize rapidly. C. it will take a stimulus of larger magnitude to initiate an
  88. BIO/SCIENCE

    If the axo-membrane becomes more permeable to potassium ions.. Which onewould be true? A. the inside of the membrane will become more positively charged. B. the membrane will depolarize rapidly. C. it will take a stimulus of larger magnitude to initiate an
  89. Physics

    A clown at a birthday party has brought along a helium cylinder, with which he intends to fill balloons. When full, each balloon contains 0.036 m3 of helium at an absolute pressure of 1.2 x 10^5 Pa. The cylinder contains helium at an absolute pressure of
  90. 6th gradeScience

    Help!!!! I can't find these answers anywhere and I don't have a science text book. 1. A tough outer covering that lies right outside the cel membrane. 2. A twisted membrane with portions that break off to form vesicles that tranport materials.
  91. Chem

    A balloonist is preparing to make a trip in a helium-filled balloon. The trip begins in early morning at a temperature of 15 degrees C. By midafternoon, the temperature has increased to 30. degrees C. Assuming the pressure remains constant at 1.00atm, for
  92. chemistry

    If four grams of Oxygen and four grams of Helium are placed in a five liter vessel at 338 K, what will be the partial pressure of each gas and the total pressure in the vessel?
  93. biology

    The function of neurons is to a. maintain a difference in electrical charge across the cell membrane. b. have specific ions cross the membrane through ion channels. c. maintain a membrane potential with charged ions on either side of the cell membrane. d.
  94. Chemistry

    A flexible plastic container contains 0.833 g of helium gas in a volume of 18.3 L. If 0.203 g of helium is removed at constant pressure and temperature, what will be the new volume?
  95. Chemistry

    A flexible plastic container contains 0.833 g of helium gas in a volume of 18.3 L. If 0.203 g of helium is removed at constant pressure and temperature, what will be the new volume?
  96. math

    A can of lemonade concentrate has a capacity of 355 mL. The concentrate is mixed with 4 cans of water. a) how much lemonade is made? b) how many 200-mL glasses can be poured?
  97. Physics

    A sample of helium behaves as an ideal gas as it is heated at constant pressure from 273 K to 353 K. If 25.0 J of work is done by the gas during this process, what is the mass of helium present?
  98. Chemistry

    A Mylar Happy Birthday balloon contains 5.15 L of helium gas at 19.4oC. If the pressure remains constant, what will be the volume of helium in the balloon, in L, when the temperature is increased by 6.6oC?
  99. Chemical Engineering

    High-pressure helium is available from gas producers in 0.045-m^3 cylinders at 400 bar and 298 K. Calculate the explosion equivalent of a tank of compressed helium in terms of kilograms of TNT. Assume helium is an ideal gas
  100. Chemical Engineering

    High-pressure helium is available from gas producers in 0.045-m^3 cylinders at 400 bar and 298 K. Calculate the explosion equivalent of a tank of compressed helium in terms of kilograms of TNT. Assume helium is an ideal gas