Angel Iwu chem- Reaction Coordinate Diagrams & Catalysts

docx

School

Purdue University *

*We aren’t endorsed by this school

Course

111/112

Subject

Chemistry

Date

Feb 20, 2024

Type

docx

Pages

3

Uploaded by Angeliwu210

Report
Activities and Explorations: 10 points, Due Sunday, April 9, 11:59 PM Kinetics, Reaction Coordinate Diagrams, Catalysts Instructions: Upload your work on this page to Brightspace by typing or writing your responses and saving the file and uploading that file as a pdf. You can also take pictures of your written work and paste them into this document and save is as a pdf. Learning Objectives 13.4 Activation Energy and Temperature Dependence of Rate Constants Identify activation energy on a Potential Energy versus Reaction progress graph. 13.6 Catalysis Define catalyst and how it impacts the rate of a chemical reaction using both words and Potential Energy versus Reaction progress graphs. Differentiate between a catalyzed and uncatalyzed reaction using a Potential Energy versus Reaction progress graph. Instructions : Answer the questions below. Be sure to show your work using mathematical calculations of drawings, as appropriate. Upload your file as a pdf into Brightspace when you are finished. Three reaction coordinate diagrams are included below. Each diagram represents a different chemical reaction (Reactions 1 – 3). Dashes lines are included to show that the potential energy axes are comparable across all three diagrams. 1. (1 pt) What significant differences can you identify between the three reaction coordinate diagrams? List at least two differences you can find. Feel free to draw on the graphs if that would help! I could tell that reaction 1 and reaction 2 have the same activation energy based on the three reaction coordinate diagrams. However, compared to reactions 1 and 2, reaction 3 has a lower activation energy. This proves that reaction 3 will have a quicker rate of response. 2. (1 pt) How do the rates of Reactions 1, 2, and 3 compare to one another? Use language such as “less than,” “greater than,” or “equal to” in your comparison. It is clear when comparing the three reactions that reaction 3 occurs at a faster rate than reactions 1 and 2. because the activation of reaction 3 was less than the activation energies of reactions 1 and 2. Based on their respective activation energies, reactions 1 and 2 also have similar rates of reaction.
3. (2 pts) Explain your answer to #2. Use specific evidence from the diagrams in question #1 in your explanation. Reaction 3 has the fastest reaction rate because, as I've already shown, its potential energy is lower than that of reactions 1 and 2. Additionally, since reactions 1 and 2 have equal potential energies, their reaction rates are also equal. 4. A reaction diagram is shown at right for the reaction A B. a. (2 pt) How would the diagram change if a catalyst was present? Explain in words and show what the new reaction diagram would look like on the graph by directly drawing on it . If a catalyst were present, the activation energy would be reduced, causing the reaction to proceed more quickly. However, the existence of a catalyst has no effect on the reaction's enthalpy. b. (1 pt) Exactly what does a catalyst do to change the the rate of the reaction? (Assume the temperature does not change.) A catalyst is an element that decreases the activation energy of a reaction to speed up the rate of the process. It accomplishes this by presenting a different reaction pathway. A subsequent step regenerates the catalyst, preventing it from being consumed in the reaction, even though it may react to form an intermediate with the reactant. A catalyst expedites a process by introducing a series of fundamental stages that have better kinetics than those that would otherwise be present. 5. (3 pts) Consider the graphs below for the reactions A and B and fill in the table. Reaction A Reaction B
Determine the activation energy and H for each reaction and whether the reaction is exothermic or endothermic. Reaction A Reaction B Activation Energy (kJ) 50 -300 H (kJ) -100 200 Exothermic or Endothermic exothermic endothermic
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help