physical chemistry

  1. P

    Radius of Gyration of an H-polymer?

    Hello, I've been struggling with determining the radius of gyration of an H-polymer. Show that the radius of gyration of an ideal H-polymer with all five sections containing an equal number (N/5) of Kuhn monomers of length b is: (R_g)^2 = (Nb^2/6)(89/625) I know the definition of the radius...
  2. C

    Mathematics of the kinetics

    Hello together, unfortunately, I do not get on with my task: Specify an expression for the concentration of A. Given is: dc(A) ------= -k1*c(A) + k2*c(B)*c(C) dt - Normally I would obey the following steps: 1. *dt =>dc(A)= (-k1*c(A) + k2*c(B)*c(C))*dt 2. Set c(A) to the left side...
  3. S

    Phase equilibria, Physical Chemistry

    The transition Sn(s, gray) ⇌ Sn(s, white) is in equilibrium at 18 °C and 1 atm pressure. If ∆S = 8.8 11K mol for the transition at 18 °C and if the densities are 5.75 g/cm3 for gray tin and 7.28 g/cm3 for white tin, calculate the transi- tion temperature under 100 atm pressure .
  4. S

    Phase equilibria, Physical Chemistry

    At 25°C we have for rhombic sulfur: ΔfG°= 0; S° = 31.88 ± 0.17 J /K/ mol ; and for monoclinic sulfur: ΔfG°=63 J/mol; S°= 32.55 ± 0.25 J/K/mol. Assuming that the entropies do not vary with temperature, sketch the value of 'μ' versus T for the two forms of sulfur. From the data determine the...
  5. S

    Phase equilibria, Physical Chemistry

    At 25°C we have for rhombic sulfur: ΔfG°= 0; S° = 31.88 ± 0.17 J /K/ mol ; and for monoclinic sulfur: ΔfG°=63 J/mol; S°= 32.55 ± 0.25 J/K/mol. Assuming that the entropies do not vary with temperature, sketch the value of 'μ' versus T for the two forms of sulfur. From the data determine the...
  6. P

    Walsh Diagrams or general chemistry diagram construction applications

    Hey all: I'm a Master's student working on a computational chemistry thesis. Up to this point, for all of my course work I've gotten away with using simple excell graphs for most of my diagrams or figures but now that I'm assembling my thesis I would like to have some nicer figures that look...
  7. T

    Co2 scrubber with sodium hydroxide and/or lithium hydroxide

    Ok, so me and a friend want to build our own co2 scrubber. After some reasearch, we narrowed down 2 substances- Sodium hydroxide and lithium hydroxide. We are wondering if anyone can help us, design and work out the chemistry needed to accomplish our task.
  8. S

    Finding pH of solution (KOH, HCl, NaCl)

    Solution made of 230 mg KOH 8.71 ml 0.802 mol/l solution of HCl 3 g m/m% NaOH = 3.97 diluted to 618 ml m/m% is weight percent of substance. What is pH of this solution?
  9. E

    Hard Kp Question!

    The table below shows initial pressures before equilibration at 600K. Calculate the equilibrium pressures. Assume that the total gas pressure is kept constant. Initial p(A) - 10.0 atm Initial p(B) - 10.0 atm Initial p(C) - 0.0 atm What I have so far: Since total pressure remains the same the...
  10. F

    Problem on most possible speed of gas

    To find the most possible speed of a gas, I know it is (2RT/M)^1/2 but how can i find out the speed of the gas mixture, let say 100:1 mixture of H2 and H2. Thank you!
  11. C

    rydberg constant

    After carrying out a spectroscopy experiment I am asked to calculate 2 values of the rydberg constant from my graph of wavenumber against 1/n2. How do I go about doing this? I have error bars so I made 2 lines (1 using the upper error and 1 using the lower errors) and then I calculated 2...
  12. S

    How to predict the products of an organic chemical reaction ?

    How to predict the products of an organic chemical reaction ? What aspects should I consider ?
  13. J

    conductivity

    After correction for the water conductivity, the conductivity of a saturated aqueous solution of AgCl at 25*C was found to be 0.1887 mS m^(-1) . What is the solubility of AgCl at this temperature? :confused: I've tried to use the Kohlrausch Law but I'm confused if the value of K is same for...
  14. J

    Entropy

    Q] Calculate the change in molar entropy when a monoatomic gas is compressed from 2.0 dm^3 to 500 cm^3 and simultaneously heated from 300K to 400K. Take Cv,m = 3R/2. I tried splitting it into a) constant volume process and b0 constant temperature process and adding the two entropies but that...
  15. J

    sublimation

    Can solids sublime at ANY temperature? If yes, please explain how.:confused:
  16. wallythewalrus

    derive an expression for the contribution of:

    Derive an expression for the contribution to the molar heat capacity at constant volume CV,m(T) of Cl atoms from these electronic states and evaluate it for T = 500 K. THEORY: The electronic ground state of the Cl atom is fourfold degenerate, while the first electronically excited state is...
  17. L

    Physical Chemistry- Units and Dimensions

    Hi everyone, I just recently started a basic module of physical chemistry in school and I am having a hard time with this one question. Could you please help me? ^^ Question: An orifice meter is used to measure the rate of fluid in pipes. The flow rate is related to the pressure drop by the...
  18. M

    Calculating FCC Surface Dipoles

    Calculate the surface dipoles for adsorption CO on Pd(111) at coverages = 0.25monolayers and coverages-0.5monolayers. Work function reduces by 1.5eV and 0.5eV respectively. I'm so confused been on this for past 4hours!! I don't understand my notes and how my lecturer has calculate b for the...