Mse217s_2007_exam - University of Toronto Department of Materials Science and Engineering Kinetics Module of RISE-21711182 FINAL EXAMINATION Monday

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: University of Toronto Department of Materials Science and Engineering Kinetics Module of RISE-21711182 FINAL EXAMINATION Monday April 16'“ 2007, 14:00—16:30 WRITE USING CA PITAL LETTER #fiwfifj FIRST NAME: LAST NAME: _ STUDENT NUMBER: SIGNATURE: l ANSWER ALL THREE PROBLEMS page I of IO pages PROBLEM 1 (MARKS 15) The tollowing elementary reaction A —> B is carried out inn plug flow reactor in which the volumetric flow rate, U , is constant. Derive an equation relating the reactor volume to the entering and exiting concentrations of A, the rate constant k, and the volumetric flow rate 1). Determine the reactor volume necessary to reduce the exiting concentration to 5% ofthe entering concentration when the volumetric flow rate is 20 lit min'l and the specific reaction rate ,k, is 0.45 min“. HINT: In a plug flow reactor the molar flow rate F obeys the following relationship: dFA (1V V Volume ofplug flow reactor :rA 1}; Rate of reaction with respect of Reactant A page 2 of IO pages pagc 3 of 10 pages PROBLEM 2 ( MARKS 15) A) During the experimentation ofthe reaction: A (fluid) + bB (solid) 6 Fluid and Solid Products 11 was found that it follows the shrinking core model. In addition results with different particle sizes have found that the "C is proportional to the particle radii. Can you deduce the mechanism which controls the conversion of particles 2’ and if not what additional tests can you suggest ? B) The same homogeneous reaction takes place in two ideal flow reactors. In both reactors the concentration of a reactant A was measured at different locations shown. From the graphs shown below can you identify the type ofreaclor( mixed flow or plug flow) ? Justify your answer L'llll‘dllUll (Kinccuzt'a‘duu (jun i ’ g A _ t.,._-_-.,___,..__ , . .. ._ .. , l’l~~i1i--t. Haw-ma: Reactor .\ Reactor ll page 4 of l“ pages C) The following reaction takes place in a batch reactor: A ——) products At time t = 0 the concentration of A is [A] = 20 mol "1'3. In this reactor you have inserted a sensitive probe which measures the concentration of A. You have found the following data: Time (min) Concentratigg of |A| in nflm" What you can say about the order ofthis reaction ? (Justify your answer) page 5 of If! pages age 6 of IO pages x page 7 of 10 pages PROBLEM 3 ( MARKS 20) Spherical panieles of Zinc Sullide. [118, of size R=l mm are roasted in a gas . . v . . . . . ‘ stream containing 8 molar % Oxygen at 900 ( and l atm. lhe storcluometry ol the reaction is: 2 7.118 + 3 01 -—> 2 ZnO + 2 SO; A) Calculate the time needed for 75% conversion ofa particle assuming: I The gas stream dilTusion through the ZnO controls and 2. The surface reaction controls B) Estimate the relative resistance of 7.110 product layer assuming complete conversion ofthe particle. Assumptions l) The above reaction proceeds by the shrinking core model, 2) The gas lilm resistance can be neglected since the 7.110 growing product layer is present, 3) The gas stream follows the ideal gas law. DEFINITIONS 1) Ttotal = Tnin‘usion + TChemical Reaction 2) Relative resistance of product layer = (TDmusion) /( 1.0m, ) DATA: 1 mol of oxygen at 273 K and l atm pressure occupies 22,400. cm}. p501“an = 4.13 gr cm'3 , Atomic Weight onn = 65.38. Atomic Weight ofS = 32.06 Reaction rate constant. k; = 2 cm sec"I Gas Dil‘fusivity in the ZnO layer Denatch : 0.08 cm2 sec‘I From the above data you can estimate the molar density. page 8 of [0 pages \a 1* ‘ I 5; 0 0| I!) pugcs page to of 10 pages ...
View Full Document

This note was uploaded on 04/28/2008 for the course MSE 217 taught by Professor Erb during the Fall '06 term at University of Toronto- Toronto.

Page1 / 10

Mse217s_2007_exam - University of Toronto Department of Materials Science and Engineering Kinetics Module of RISE-21711182 FINAL EXAMINATION Monday

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online