Search results

  1. J

    I know that when you hyperventilate, the Pco2 in blood decreases

    I know that when you hyperventilate, the Pco2 in blood decreases... but is it the venous or arterial PCo2 that's decreasing? Can someone please clarify this? Thank you!
  2. J

    Questions about oxygen level in humans

    1. The % of hemoglobin bound with Oxygen is different at high and low carbon dioxide concentrations when the partial pressure of O2 equals 0mm Hg True or false?? This should be false right...? if partial pressure is 0... Hb can't bind to any oxygen in the first place... is my reasoning...
  3. J

    Please help! ion channels? voltage?

    Whole-cell patch clamp electrophysiology can be used to record: a. the activity of the ion channels that are present in the patch of membrane. b. the activity of multiple neurons at a given time. c. voltage and/or current across the membrane of a cell. d. multi-unit activity...
  4. J

    Some questions about neuro stuff

    Whole-cell patch clamp electrophysiology can be used to record: a) the activity of the ion channels that are present in the patch of membrane b) the activity of multiple neurons at a given time c) voltage and/or current across the membrane of a cell d) multi-unit activity My guess: c...
  5. J

    Data acquisition for waves

    If your MP100 is recording at 10 sps and your input analog signal is at 100Hz, how many waves would the data acquisition miss in a 5 s recording? a. 50 b. 1000 c. 25 d. 500 e. 100 This means that you're sampling every 10 cycles. Then you miss 9/10. so once it goes through 100 cycles...
  6. J

    Maclaurin series coefficient

    Homework Statement find coefficient of x^4 in the MAclaurin series for f(x)=e^sinx Homework Equations ok... so taking derivatives 4 times for this function.....gave me a mess!!! @.@ can someone help me in simplying the derivatives...? 1. cosxe^sinx then for 2. is it...
  7. J

    Series; convergence, divergence

    series; convergence, divergence.... Homework Statement 1. sum(infinity,n=1) n!/1.3.5...(2n-1) 2. sum(infinity, n=1) (-1)^n arcsin(-1/n) 3. sum(infinity, n=0) arcsin(1/n^2) / arctan(1/n^2) The Attempt at a Solution 1. i used the ratio test and then i ended up with lim((n+1)(2n-1)/2n+1))...
  8. J

    Integral problem

    suppose that f is continuous and (integral]0->2 f(x)dx = 6. Then (integral]0 -> pi/2 f(2sinb)cosbdb=? ok.... i'm totally lost here... how do u solve this without knowing what f(x) is..????
  9. J

    Arclength question

    this is a really easy question... but seems like i keep getting something wrong in my calculations... - - Find the arclength of y = x^3/2 0<x<5/9 when i do it using the formula; L = sqreroot (1+(dx/dy)^2) i keep getting one... can someone post the calculation process.....
  10. J

    Rolling motion?

    A uniform, spherical bowling ball of mass m and radius R is projected horizontally along the floor at an initial velocity v0 = 6.00 m/s. The ball is not rotating initially, so w0 = 0. It picks up rotation due to (kinetic) friction as it initially slips along the floor. The coefficient of...
  11. J

    Separation of solid mixture by extraction

    Hi, I have a question about separation of solid mixture by extraction. so how can you tell what reacts with what and which layer contains what? k for example, if you have a mixture of phenol and salicylic acid, first the mixture is dissolved in diethyl ether... then the solution is mixed with...
  12. J

    Energy barrier?

    What's an energy barrir to rotation? I have data on the enrgy at anti and gauche conformations of 1-iodopropane. I have also graphed the data (steric energy vs dihedral angle) from the graph, do I just subtract the trough at anti from the trough at gauche? so from anti to gauche, it'd be...
  13. J

    Melting point and solubility in water of benzoic acid

    in literature, find melting point and solubility in water of benzoic acid, vanillin, phthalic acid, salicyclic acids. Calculate the expected volume of hot water that would be requried to dissolve 0.15g of each compound. With info on melting point and solubility in water... how can you...
  14. J

    Gauche and anti of n-butane

    The difference in energy between gauche and anti of n-butane is 3.6kJ/mol. For the molecule iodobutane, I found the differnece in energy between the gauche and anti to be about 0.62KJ/mol... What accounts for this difference??? and also, when you're asked to find the energy barriers to the...
  15. J

    What is the geometry of dichloromethane?

    organic chem!! What is the geometry of dichloromethane?? Before optimization, Cl-C-Cl bond is 109.5, H-C-Cl bond is 67.8... so it must be tetrahedral... but after optimization, do the angles get bigger?? why? and also, the bond length increases... Why do angles and the bond length in...
  16. J

    Bond angles

    How is the bond angle for Cl-C-Cl in dichloromethane different from H-C-H bond angle of CH4? Is it smaller??
  17. J

    HELP NEEDED ! regarding distillation.

    HELP NEEDED!!!!!! regarding distillation................ Hi I am in need of desperate help with chemistry... So we did a simple distillation of an unknown alcohol and after the distillation, we were to identify what the alcohol is.. My result was that i got my first drop of distillate at...
  18. J

    Kepler's law?

    Planet X orbits the star Alpha with a 'year' that is 200 earth days long. Planet Y circles Alpha at nine times the distance of planet X. How long is a year on planet Y? I know that I have to use the kepler's law : T^2 = (4pi^2/GM)r^3 but I'm not too sure how to do solve this... Please...
  19. J

    Simple distillation

    What happens to an azeotrope during simple distillation?? for example 1-propanol + water... which I have asked here before.. but still not clear... but also, when you graph the boiling point-composition diagram and look at a specific composition, you read off when the liquid equilibrium is...
  20. J

    Distillation question~

    Hi, I think this is a simple enough question for all the chemists out there~ but for me it's tough... :( so we did a simple distillation experiment. We were given an unknown alcohol to identify. I found the boiling point to be about 89degrees which matched the boiling point of the...
  21. J

    Dynamics question!

    A window washer of mass M is sitting on a platform suspended by a system of cables and pulleys. He is pulling on the cable with a force of magnitude F. The cables and pullys are ideal (massless and frictionless), and the platform has negligible mass. So the situation here is that the...
  22. J

    Calculations and probability

    How do yo do these calculations?? help plz! for ex would a + b be, 90.043 ± 14.344??? Calculate: (a) 23.043 ± 4.321 (b) 67 ± 9.023 (c) 33.1492934 ± 2 a = 40 ± 5 b = 30 ± 3 c = 20 ± 1 t = 1.2 ± 0.1 Calculate a + b, a + b + c, a / t, and (a + c) / t. Calculate (1.23 ± 0.03) +pi...
  23. J

    More probability

    more probability.... ok, so we're given a histogram showing the sum of numbers when dice is rolled certain number of times. it was seen that the higher the number of rolls, the closer the result of sum was to the theoretical prediction. so 7 is the most likely sum that would occur when u roll...
  24. J

    Boiling point?

    boiling point?? What is a literature boiling point?? Is it the same thing as just normal boiling point? What does this temperature tell us in regards to distillation of alcohol? (alcohol properties)
  25. J

    Purpose of distillation?

    What are the three purposes of distillation?? I only know the main purpose of distillation, which is to separate liquid mixture into two or more products with different compositions... I can't come up with three purposes!! :(
  26. J

    Sooo lost please help (probablility? problem)

    sooo lost... please help!!! (probablility? problem) So, we were given simulations of histograms that has to do with rolling a certain number of dice consecutive times. and these questions were given... and I am soo lost as to how to approach these questions. 1. What is a reasonable...
  27. J

    Chemical reactions with ether?

    chemical reactions with hydrochloric acid does p-toluidine hydrochloride dissolve in HCl?? When it combines with HCl, what would it produce???
  28. J

    Solubility and chemical equations

    Does p-toluidine hydrochloride dissolve in water, HCl, NaOH, or NaHCO3? How would you write the chemical equations of the reactions?? if a salt is formed... how do you write that in an equation showing the structural formulas?? If it dissolves in water, if you add drops of HCl or NaOH to the...
  29. J

    Can sodium sulphate, p-toluidine, and benzoic acid form hydrogen bond

    can sodium sulphate, p-toluidine, and benzoic acid form hydrogen bond with water?
  30. J

    Projectile prblem

    I have a question about a projectile motion problem. So the background info of this problems is that a quarterback is throwing a football to a receiver who's running with constant v_r and he's now D distance away from the quarterback. The quarterback thinks that it should be thrown at angle...