Chemical Kinetics: Mini Journal Lab Report

Introduction and Planning

Introduction

Mini journal focusing on chemical kinetics and reaction order. This type of learning environment is a more authentic approach and similar to the upper chemistry course setting. The reaction that you will be working with is hydrogen peroxide and iodide ion in an acidic environment, in the presence of thiosulfate ion and starch indicator as shown in Figure 1. Iodideion is oxidized by hydrogen peroxide to iodine, which is reduced back to iodide ion immediately by thiosulfate ion. With depletion of thiosulfate ion, the concentration of iodine will stabilize and form a blue color with starch.

H2O2 + 2I- + 2H+ → I2- + 2 H2O

2S2O32- + I2 → 2I- + S4O62-

I2 + starch → blue complex.

Introduction and Planning

A class discussion will be led by your lab instructor to introduce what’s included in the minijournal lab (see last section in this lab manual). Questions that will be discussed are the following:

1. What are the research questions and why are they important?
2. What is the hypothesis?
3. What are the materials and methods for experimental investigations?
4. What data and evidence have been collected?
5. How is the data analyzed and what are the findings? Are they reasonable?
6. What are the follow-up research topics?

 In the rest of the class, each group will generate their own research question using the following cases as foundation, formulated hypothesis, designed material needs, experimental procedures, outlined tables and graphs for data collection and analysis. You may also use the rest of the lab period to practice experimental techniques with glassware and instruments as accuracy is part of the grading criteria.

Solution Provided

The following chemicals will be provided in this project:

0.05 M buffer solution of acetic acid-sodium acetate at pH 4.6
0.05 M potassium iodide solution
0.1 % starch solution
0.05 M sodium thiosulfate solution
0.8 M hydrogen peroxide solution

Data collection + Data analysis

Provided with the supplied instruments and chemicals, you will be conducting the experiments, analyzing and evaluated results, trouble-shot procedures and recollect data, if necessary, in this lab session.

Mini journal

Mini journal writing guide and rubric:

The mini-journal lab report should be typed with no less than 1” margin, double line spacing and 12-point font, Times New Roman in all numbered pages. Tables and graphs must be produced by computer for best illustrations. Do not allow tables to crow pages. Your mini journal should include following sections:

Proposal of the research questions and their importance. Review of what is already known for the topics. Description of the investigation plan to answer the research questions and the expected findings.

Materials and Methods

A narrative format with enough details of materials and experimental methods. It should allow someone else trained in the field to repeat your work and arrive at similar results.

Display of direct experimental results in tables and or graphs. Calculations and analysis for data treatments. Appropriate significant figures in correspondence with instruments and analysis. Statistics of data such as average and standard error for multiple trials.Discussion (250-350 words): Restatement of the questions and narrative of the results. Conclusions and findings based on results, which approve or disapprove the hypothesis. Alternative explanations in science context. Suggestions for future research topics and potential improvements.

Conclusion

Summary of the main sections of the paper, include research questions and related background; the hypothesis; investigation methods and results, and conclusions and discoveries in answering the original questions.