Topic outline

  • General

    • Course Summary: Show more...
      Enrol me in this course
    • Announcements Forum
      Not available unless: You are a(n) Student

  • Interface Mass Transfer

    • Checklist
      Students must
      Check-off items: 90%
    • Transfer of Solute from Gas to Liquid - Two-film Theory Page
      Not available unless: You are a(n) Student
    • Controlling Resistance from Individual Mass Transfer Coefficients Page
      2000-2-14-mt
      The individual mass transfer coefficients (mol/m2.s) for absorption of a solute from a gas mixture into a liquid solvent are \(k_x\) =4.5 and \(k_y\) = 1.5. The slope of the equilibrium line is 3. Which of the following resistance(s) is (are) controlling?
      1. liquid-side
      2. gas-side
      3. interfacial
      4. both liquid and gas side
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Relative Resistances from Concentration Difference Page
      Students must
      Mark as done
      2017-16-mt
      Consider steady state mass transfer of a solute \(A\) from a gas phase to a liquid phase. The gas phase bulk and interface mole fractions are \(y_{A,G}\) and \(y_{A,i}\), respectively. The liquid phase bulk and interface mole fractions are \(x_{A,L}\) and \(x_{A,i}\), respectively. The ratio \(\dfrac {(x_{A,i}-x_{A,L})}{(y_{A,G}-y_{A,i})}\) is very close to zero. This implies that mass transfer resistance is
      1. negligible in the gas phase only
      2. negligible in the liquid phase only
      3. negligible in both the phases
      4. considerable in both the phases
      Enrol me in this course
    • Absorption of Solute where Ky=ky Page
      1990-5-i-mt
      In the absorption of a solute gas from a mixture containing inerts in a solvent, it has been found that the overall gas transfer coefficient is nearly equal to the individual gas film transfer coefficient. It may therefore be concluded that:
      1. the process is liquid film controlled
      2. the gas is sparingly soluble in the solvent
      3. the transfer rate can be increased substantially by reducing the thickness of the liquid film
      4. the transfer rate can be increased substantially by reducing the thickness of the gas film
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Resistance for Solute with Less Solubility in Liquid Page
      1998-1-17-mt
      In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be
      1. liquid phase resistance controlled
      2. gas phase resistance controlled
      3. impossible
      4. driven by a nonlinear driving force
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Conditions for Absorption to become Gas-film Controlled Page
      2012-18-mt
      For which of the following operations, does the absorption operation become gas-film controlled?
      • [P.] The solubility of gas in the liquid is very high
      • [Q.] The solubility of gas in the liquid is very low
      • [R.] The liquid-side mass transfer coefficient is much higher than the gas-side mass transfer coefficient
      • [S.] The liquid-side mass transfer coefficient is much lower than the gas-side mass transfer coefficient
      1. P & Q
      2. P & R
      3. P & S
      4. Q & R
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Controlling Resistance for Absorption of CO2 in Amine Page
      2014-19-mt
      Assuming the mass transfer coefficients in the gas and the liquid phases are comparable, the absorption of CO2 from reformer gas (CO2+H2) into an aqueous solution of diethanolamine is controlled by
      1. gas phase resistance
      2. liquid phase resistance
      3. both gas and liquid phase resistances
      4. composition of the reformer gas
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Absorption of H2S in Amine - Controlling Resistance Page
      Not available unless: You are a(n) Student
    • Absorption of Sparingly Soluble Gas in Liquid Page
      Not available unless: You are a(n) Student
    • Gas-film Thickness from Diffusion Rate and Interface Concentration Page
      1991-6-i-mt
      The diffusion rate of ammonia from an aq.solution to the gas phase is \(10^{-3}\) kmol/m\(^2\).s. The interface equilibrium pressure of \(\ce {NH3}\) is 660 N/m\(^2\) and the concentration of \(\ce {NH3}\) in the gas phase is 5%. If the total pressure is 101 N/m\(^2\), temperature is 295 K and diffusivity of \(\ce {NH3}\) is 0.24 cm\(^2\)/s, the gas film thickness is ____________(\(\mu \)m).
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Concentration Profile for Absorption of Solute Page
      Not available unless: You are a(n) Student
    • Molar Flux and Interfacial Concentration Page
      1990-15-iii-mt
      Consider a system in which component \(A\) is being transferred from a gas phase to a liquid phase. The equilibrium relation is given by \(y_A = 0.75 x_A\) where \(y_A\) and \(x_A\) are mole fractions of \(A\) in gas and liquid phase respectively. At one point in the equipment, the gas contains 10 mole % \(A\) and liquid 2 mole % \(A\). Gas film mass transfer coefficient \(k_y\) at this point is 10 kmol/(h.m\(^2\).\(\Delta y_A\)) and 60% of the resistance is in the gas film. Calculate:
      1. the overall mass transfer coefficient in kmol/(h.m\(^2\).\(\Delta y_A\))
      2. mass flux of \(A\) in kmol/(h.m\(^2\))
      3. the interfacial gas concentration of \(A\) in mole fraction
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Colburn j-factor of Mass Transfer Page
      Not available unless: You are a(n) Student
    • Mass Transfer Correlation in terms of jD Factor Page
      Not available unless: You are a(n) Student
    • Reynolds Analogy - Applicability Page
      Not available unless: You are a(n) Student
    • Correlation for Heat Transfer from that of Mass Transfer Page
      Not available unless: You are a(n) Student
    • Time for Complete Sublimation Page
      2019-50-mt
      Two spherical camphor particles of radii 20 cm and 5 cm, far away from each other, are undergoing sublimation in a stream of air. The mass transfer coefficient is proportional to \(1/\sqrt {r(t)}\), where \(r(t)\) is the radius of the sphere at time \(t\). Assume that the partial pressure of camphor far away from the surface of the particle is zero. Also, assume quasi-steady state, identical ambient conditions, and negligible heat effects. If \(t_1\) and \(t_2\) are the times required for complete sublimation of the 20 cm and 5 cm camphor particles, respectively, the ratio \(t_1/t_2\) is ________ .
      Enrol me in this course
      Not available unless: You are a(n) Student
    • Unsteady Dissolution of Solute Page
      Not available unless: You are a(n) Student
    • Rate of Dissolution from Mass Transfer Coefficient Page
      Not available unless: You are a(n) Student
    • Significances of Prandtl Number and Schmidt Number Page
      Not available unless: You are a(n) Student
    • Sherwood Number for Diffusion of Water in Air Page
      Not available unless: You are a(n) Student
    • Interfacial Area from Hold-up Data Page
      Not available unless: You are a(n) Student