Search results

  1. A

    Buffer Capacity

    oops... i think i got the answer... thanks
  2. A

    Buffer Capacity

    What is the smallest amount of solid NaOH that will exceed the buffer capacity 500mL of a buffer that is 0.4M in acetic acid and 0.15M in NaOAc? a)5.69 b)5.16 c) 4.74 d) 4.31 e)3.00 grams Since this is a strong base, we only need to deal with the 0.4M of acetic acid. so 0.4M *.5L =...
  3. A

    Partial Pressure Equilibrium lab

    The problem is, if you try using your way, it will be very difficult to figure the answer out. I used a different method, and I got the answer. Thanks anyways.
  4. A

    Partial Pressure Equilibrium lab

    Pure solid ammonium carbamate, NH4CO2NH2, is allowed to dissociate into a vacuum according to the equation: NH4CO2NH2(s) ---> 2 NH3(g) + CO2(g) At 25oC, the total pressure of the gases in equilibrium with the solid is 0.116 atm. If carbon dioxide, CO2, was then added, sufficient to have...
  5. A

    Joined Spring problem

    they are on the same side
  6. A

    Limit problem

    I take it as, there's no solution to this problem. Either I'm reading the question wrong, or the prof wrote the question wrong. This is because for any other problems in this exercise, the limit did exist, so I'm sceptical as to whether the answer is infinity.
  7. A

    Oscillation of object on spring - Find speed

    A massless spring hangs from the ceiling with a small object attached to its lower end. the object is initially held at rest in a position y such that the spring is at its rest length(not stretched). The object is then released from y and oscillates up and down, with its lowest position being 10...
  8. A

    Joined Spring problem

    So Equivalent spring is = (1/k1 + 1/k2 + 1/k3.... 1/kn)^-1 where kn is the spring constant for each component ? This is based on what you said. This is how I would approach it: Let's say there are only 2 springs connected in series. We can calculate the ratio between the distances...
  9. A

    Limit problem

    How do you find the limit to: Lim x->0+ sqrtx/(1-cosx) I use the L'Hopital rule and i get lim x->0+ 1/(2sqrtx*sinx) and I can't get anywhere after this. I even tried multiplying by sqrtx/sqrtx to get rid of the sqrtx at the beginning, but it still doesn't work. Please help, thanks.
  10. A

    Joined Spring problem

    Two springs with a spring constant of k = 6430 N/m are joined and connected to a block of mass 0.245 kg. The system is then set oscillating over a frictionless surface. What is the frequency of the oscillations? This is what I think is the correct approach to this question: since the...
  11. A

    Limit problem

    How do you find the limit to: Lim x->0+ sqrtx/(1-cosx) I use the L'Hopital rule and i get lim x->0+ 1/(2sqrtx*sinx) and I can't get anywhere after this. I even tried multiplying by sqrtx/sqrtx to get rid of the sqrtx at the beginning, but it still doesn't work. Please...
  12. A

    Oscillating spring problem

    A massless spring hangs from the ceiling with a small object attached to its lower end. the object is initially held at rest in a position y such that the spring is at its rest length(not stretched). The object is then released from y and oscillates up and down, with its lowest position being 10...
  13. A

    Joined Springs

    they are in series As well, how would some one solve a problem like this, if the springs were not identical?
  14. A

    Joined Springs

    Two springs with a spring constant of k = 6430 N/m are joined and connected to a block of mass 0.245 kg. The system is then set oscillating over a frictionless surface. What is the frequency of the oscillations? This is what I think is the correct approach to this question: since the...
  15. A

    Hexyl ethanoate or octanoic acid?

    Which is more soluble in hexane, hexyl ethanoate or octanoic acid? I'm thinking it's octanoic acid with the longer uninterrupted hydrocarbon chain, where as the ester's longest uninterrupted hydrocarbon chain is composed of six carbons. Is this correct? If not can you please explain why? Thanks.
  16. A

    Cyclohexene and toluene + sulfuric acid

    For cyclohexene and sulfuric acid reaction, is a precipitate suppose to form? the results looked yellow-orange ish, but it became murky. I'm suppose to note the solubility change, but i don't know what to say for it. Please help thanks. For Toluene though, i heated it as well, and there was...
  17. A

    Toluene + bromine

    I mixed toulene + bromine and dichloromethane together, to see if a reaction occurs(decolourizes). However, i read in my lab manual that this test should be negative for aromatics. So is toluene suppose to be negative as well? If so i think something went wrong with my experiment. Thanks.
  18. A

    Proving inflection points - Titration

    I think he's just using it as an example, even though it might be wrong. The concept is still there. However, i still need help proving the inflection points. I'm just curious as to how it's done. Thanks.
  19. A

    Proving inflection points

    I know this is a chem question in general, but the steps needed to solve this are more mathematical. This is not a homework question, but my prof came up with the concept of determining the inflection point on a titration graph with 2 pKas. He simply told us that it was the average of the 2...
  20. A

    Proving inflection points - Titration

    This is not a homework question, but my prof came up with the concept of determining the inflection point on a titration graph with 2 pKas. He simply told us that it was the average of the 2 pKa values. However, he also just mentioned that it can also be proven through calculations, but he never...
  21. A

    Calculating pKa

    I'm using lehninger, Principles of Biochemistry... Not enjoying it much, the problems that is.
  22. A

    Calculating pKa

    An unknown compound, X is thought to have a carboxyl group with a pKa of 2.0 and another ionizable group with a pKa between 5 and 8. When 75 mL of 0.1 M NaOH was added to 100mL of a 0.1 M solution of X at pH 2.0, the pH increased to 6.72. Calculate the pKa of the second group of X. ok...
  23. A

    Dissociation of glycine

    Thanks for your help
  24. A

    Dissociation of glycine

    Here's the problem how much of 5M KOH should be added to 1L of 0.1M glycine(pKa=9.6) at a pH of 9 until the pH reaches exactly 10? the answer in the back says 10mL. R-NH3(+) <-> R-NH2 + H(+) Here's the way I solved it. I figured out the number of moles of R-NH2 using the...
  25. A

    Pulley accelerations problem

    That's not what's he's saying, and that's not correct Ax = -Ay. Swatch, himanshu is trying to explain to you how the magnitude of the acceleration in the x direction is equal to twice the magnitude of the acceleration of the second object in the y direction.
  26. A

    Fluid Submersion Question:

    the density of oil is not 0.639.
  27. A

    Fluid Submersion Question:

    The volume has not been divided out completely. Reread OldDan's previous posts more carefully, about drawing out the soap... X and Y are the heights of the soap subermerged in each liquid... just read the previous posts more carefully
  28. A

    Fluid Submersion Question:

    Uhh... the force of buoyancy of water changes only because the force of buoyance of oil also contributes to keep the soap afloat. It's the same principle; the weight of the both fluids displaced equals to the weight of the soap. So set up an equation(s) to find the volume of oil displaced and...
  29. A

    Young Exp (Bright)

    Ok, what must be true to have both diffraction gratings to coincide with each other? Don't mind the distances yet....
  30. A

    Fluid Submersion Question:

    You don't need to include Fbw 1 and 2 (I assume you're thinking that these are the weight of the fluids?) As Archemides principle says, the buoyant force equals to the weight of the fluid displaced. You already have the weight of the fluid from Fbo. There are 2 fluids which the soap...
Top