posted by .

The diffusion coefficient for calcium ions crossing a biological membrane 10nm thick is 300 micrometers squared/second and the concentration difference of calcium ions across the membrane is 400 mol/m^2 (Molar mass of calcium is 40 kg/mol)
Determine the number of moles of calcium ions that move through a 1 micrometer*1 micrometer cross sectional area of the membrane in 1 second

  • physics -

    Diffusion rate (moles/area*sec) =
    (Concentration gradient)*(Diff. coefficient)

    Shouldn't the concentration difference have units of mole/m^3 ? Or are you providing the value of
    (Diff. coefficient)/(thickness) ?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    1. Calculate the volume of carbon dioxide at 273 K and 1.01 * 10^5 Pa which would be produced when 1.25g of calcium carbonate reacts completely with HCL. and 2. When 41.18 cm^3 of a solution of silver ions with concentration of .2040 …
  2. AP Chem

    An aqueous solution contains 4.50 g of calcium chloride, CaCl2, per liter. What is the molarity of CaCl2?
  3. chemistry

    Water softeners often replace calcium ions in hard water with sodium ions. Since sodium compounds are soluble, the presence of sodium ions in water does not cause the white, scaly residues caused by calcium ions. However, calcium is …
  4. 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 …
  5. Gen Chemistry

    52.8 mL of a calcium chloride solution with unknown concentration was treated with phosphoric acid to remove all of the calcium ions in the form of a precipitate. The precipitate was filtered, dried and was found to have the mass of …
  6. chem

    The daily RNI of calcium for adolescent females is 700 to 1100 mg. A supplement tablet contains 950 mg of calcium citrate. Each grams of calcium citrate contains 5.26 x 10^-3 mol calcium. How many tablets would a 16 year old female …
  7. chemistry 11

    Food manufacturers sometimes add calcium acetate to puddings and sweet sauces as a thickening agent. What volume of 0.500 mol/L calcium acetate, Ca(CH3COO)2 (aq), contains 0.300 mol of acetate ions?
  8. Chemistry

    Calcium hydroxide has Ksp = 5.5 x 10-5 at 25 oC and a molar mass of 74.10 g/mol. How many grams of calcium hydroxide are needed to create 365 mL of a saturated solution of calcium hydroxide at 25 oC?
  9. chemistry

    1. How many grams of calcium chloride (CaCl2) are there in 600.0 mL of an aqueous solution that has a concentration of 0.450 M CaCl2?
  10. Chemistry

    In a discussion,a study argued that calcium ions when asded to toothpaste would enhance the performance of the toothpaste by further strengthening teeth. Therefore, he suggested the addition of calcium hydrogen carbonate, calculate …

More Similar Questions