The hydrogenation of acetylene (C2H2) on Pd metal sites (*) is proposed to occur via elementary steps consisting of: 1) QE dissociative adsorption of H2: 2) QE molecular adsorption of C2H2; 3) & 4) QE sequential addition of H" to form C:Ha"; 5) Irreversible desorption of ethylene. Write the mechanism of the reaction with the stoichiometric number of each step. Derive the rate expression in terms of constants and measurable quantities when C:H," and " are the MARI. If C;H, is in the MARI expression, why is the rate independent of the concentration of C¿H4 in the gas phase? At some conditions, the experimental rate is zero order in both CH2 and H2. What additional assumption(s) are required for this observation to be consistent with the rate expression derived in part (b)? 1) If, under certain experimental conditions, an effective zero order rate constant is measured, explain the chemical significance of this constant (in terms of rate or equilibrium constants for elementary steps) using the rate expression in part (b).

Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
icon
Related questions
icon
Concept explainers
Question
4. The hydrogenation of acetylene (C2H2) on Pd metal sites (*) is proposed to occur via
elementary steps consisting of: 1) QE dissociative adsorption of H2; 2) QE molecular
adsorption of C2H2; 3) & 4) QE sequential addition of H* to form C2H4*; 5) Ireversible
desorption of ethylene.
(a)
Write the mechanism of the reaction with the stoichiometric number of each step.
(b)
Derive the rate expression in tems of constants and measurable quantities when CH,*
and * are the MARI. If C;H4 is in the MARI expression, why is the rate independent of
the concentration of C¿H4 in the gas phase?
(c)
At some conditions, the experimental rate is zero order in both CH2 and H2. What
additional assumption(s) are required for this observation to be consistent with the rate
expression derived in part (b)?
If, under certain experimental conditions, an effective zero order rate constant is
measured, explain the chemical significance of this constant (in terms of rate or
equilibrium constants for elementary steps) using the rate expression in part (b).
(d)
Transcribed Image Text:4. The hydrogenation of acetylene (C2H2) on Pd metal sites (*) is proposed to occur via elementary steps consisting of: 1) QE dissociative adsorption of H2; 2) QE molecular adsorption of C2H2; 3) & 4) QE sequential addition of H* to form C2H4*; 5) Ireversible desorption of ethylene. (a) Write the mechanism of the reaction with the stoichiometric number of each step. (b) Derive the rate expression in tems of constants and measurable quantities when CH,* and * are the MARI. If C;H4 is in the MARI expression, why is the rate independent of the concentration of C¿H4 in the gas phase? (c) At some conditions, the experimental rate is zero order in both CH2 and H2. What additional assumption(s) are required for this observation to be consistent with the rate expression derived in part (b)? If, under certain experimental conditions, an effective zero order rate constant is measured, explain the chemical significance of this constant (in terms of rate or equilibrium constants for elementary steps) using the rate expression in part (b). (d)
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Aromatic Compounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY