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# Test: Multicomponent Diffusion

## 5 Questions MCQ Test Mass Transfer | Test: Multicomponent Diffusion

Description
This mock test of Test: Multicomponent Diffusion for Chemical Engineering helps you for every Chemical Engineering entrance exam. This contains 5 Multiple Choice Questions for Chemical Engineering Test: Multicomponent Diffusion (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Multicomponent Diffusion quiz give you a good mix of easy questions and tough questions. Chemical Engineering students definitely take this Test: Multicomponent Diffusion exercise for a better result in the exam. You can find other Test: Multicomponent Diffusion extra questions, long questions & short questions for Chemical Engineering on EduRev as well by searching above.
QUESTION: 1

### A mixture undergoing multicomponent diffusion is analyzed through the Maxwell-Stefan approach. With regard to this approach which among the following statements are incorrect? The difference in the partial pressure of the Component A over a small distance ∆z (AB)is proportional to

Solution:

Explanation: Factual.

QUESTION: 2

### If all the components except 1 of the multicomponent diffusing mixture are inert, then what will be the expression for Diffusivity of the component 1 in the mixture?

Solution:

Explanation: For an inert component Nj=0.

QUESTION: 3

### A mixture of 60% hydrogen and 40% oxygen is blowing over a pan of water at 1atm pressure. The bulk gas temperature is 30°c and the water temperature is 20°C. The vapor pressure of water at this temperature is 17.53mm Hg. The concentration of moisture in the bulk gas is negligible and the diffusivity values are DO2-H2O=0.357cm2/s,DH2-H2O=0.972cm2/s at 34°C and DH2-O2=0.891cm2/s at 43°C. Q. Which of the following statements are correct?

Solution:

Explanation: Water vapor has a source (pan) as well as a sink (bulk gas) whereas hydrogen and oxygen has no sink.

QUESTION: 4

A mixture of 60% hydrogen and 40% oxygen is blowing over a pan of water at 1atm pressure. The bulk gas temperature is 30°c and the water temperature is 20°C. The vapor pressure of water at this temperature is 17.53mm Hg. The concentration of moisture in the bulk gas is negligible and the diffusivity values are DO2-H2O=0.357cm2/s,DH2-H2O=0.972cm2/s at 34°C and DH2-O2=0.891cm2/s at 43°C.

Q. What will be the values of the diffusivities (in cm2/s) at the mean gas-film temperature?

Solution:

Explanation: Use the relation D∝T1.75
Mean gas-film temperature= (30+20)/2=25°C.

QUESTION: 5

A mixture of 60% hydrogen and 40% oxygen is blowing over a pan of water at 1atm pressure. The bulk gas temperature is 30°c and the water temperature is 20°C. The vapor pressure of water at this temperature is 17.53mm Hg. The concentration of moisture in the bulk gas is negligible and the diffusivity values are DO2-H2O=0.357cm2/s,DH2-H2O=0.972cm2/s at 34°C and DH2-O2=0.891cm2/s at 43°C.

Q. What is the value of the flux (kmol/m3.s) of water vapor through a stagnant film of estimated thickness 1.5mm on the water surface?

Solution:

Explanation: Calculate D1m from the equation, D1m=(1-Y1)/(∑〖Yj/Dij〗)
D1m=0.465cm2/s
Use the equation, N1=(D1mC/l)*ln⁡〖(1-Yil)/(1-Y10)〗, where Yil=0(dry air) and Y10=0.023 (17.53/760).