IMG_0004_NEW_0029

# IMG_0004_NEW_0029 - :reactive intermediate d[Nzotl-o Stcrdy...

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t I L\$ T.DAY,S LECTURE: ..REACTION KINETICS'' Steady-state approxim ation Temperature Dependence of Reaction Rates Steady-State Approxi mati on In a multiple step reaction: k, k, A+B _-i* Intermediar"t products Can't choose a rate determining step? + use "STEADY STATE" approximation: Concentration of reactive intermediates remains constant as the reaction proceeds d[Irfernredia tes] --A dt Find rate law for reaction Example: Reactive lntermediates 2NO+IIr+N'O+H2O ' Suggesedmechanism Step 1 k1 2t*o - NzOz ft-1 Step 2 k2 IQQ+lJo+ N2O+H2O . NzOz
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Unformatted text preview: :reactive intermediate d[Nzotl -o Stcrdy stete approximation dt Y = ^[No]' -r-,[N,o,] - hlN,o,llH,l = o Solve for [N2O2]: [NrOr]= Overall Rate Law GOAL: To write the overall rate law without including any intermediates In terms of the Consumption of Hr: Step 1 k1 2NO =- NzOz k_1 Step 2 k2 N2Or+Hz+ NrO+HrO Rate : -ry1= frr[Nror][Hr] dt But. ..we don't want the concentration of an intermediate in the overall rate law + Substitute expression for [N2O2] Rate = 4k'?[No]'zlH,l k_r+krlHrf 4...
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## This note was uploaded on 12/27/2011 for the course CHEM 122 taught by Professor Williams during the Fall '10 term at Simon Fraser.

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