Performance Assessment Lab

This is an assessment of your individual ability to design and perform a laboratory experiment. You are to work only with your lab partner or alone. Any consultation for any reason with any other student/person is considered cheating and may result in a zero for the entire project. All procedures used must be original work designed by you using only the information gathered about reaction rates and kinetics through research and experimentation. USING ANY PROCEDURES NOT DESIGNED BY YOU IS NOT ALLOWED.

PROBLEM:

Using concentration and/or temperature as your variable(s), design and perform an experiment that produces a color change at an assigned time.

BACKGROUND:

solution A + solution B color change

There will be 5 different solutions of each A and B of varying concentration available. You will choose one to work with throughout the lab.

It is your responsibility to research any and all additional background information before you start your experiment. The more thorough your research, the more successful your experience will be. It is imperative you have a detailed working knowledge of reaction rates for this lab.

PROCEDURE:

  • Each day your lab group will come prepared with a prelab for the information to be collected that day. Your lab book should include all scientifically acceptable data tables, proceduresand expectations for that day.
  • Procedures must be specific with amounts, timing methods and directions. Make them REPEATABLE.
  • Your lab group will be given 40 mL of each solution each day. The total volume of added solutionsincluding water should not be more than20. mL and each test tube should have the same total volume before reaction. (This eliminates volume as a variable.)
  • You are required to keep a daily journal in your lab book that includes directions/observations for the day, procedural changes, new ideas, thoughts/conclusions, errors, etc. This should be kept for each day you spend in the lab. Be sure you have complete documentation of your daily work. DOCUMENT YOUR LEARNING PROCESS!!!
  • You should strive to have at least 3 trials/data points per experiment.
  • Your final results will be turned in at the end of each period.
  • Questions will be answered by the instructor no earlier than the end of day 3.

EVALUATION:

This is a formal assessment as well as a lab experiment. Your formal lab write up will be approximately 100 points in the quiz/test category. Your lab skills and ability to design and carry out an experiment will be worth another 100 points in the lab category. This is determined by how close your reaction rate is to your assigned time (see chart). Your lab journal that includes all final procedures, data tables, observations, etc will also be add another 30 points in the lab category.

The formal lab write-up will be graded according to the attached point schedule. It must exemplify complete understanding of lab techniques and design and include a thorough discussion of all scientific concepts studied in this lab. No late labs will be accepted.

For each day in the lab, students will receive daily participation points (for a total of 40 points),that will be included in the assignment category, based on time management, preparation for the day and data collection. Students should be prepared to orally explain what, why and how the procedure being used fits into or helps them with the overall problem being studied.

SCHEDULE:

Day 1

Introduce problem

Day 2

Determine the effect of heat on the rate of a reaction. Conclusions must be supported with viable procedure and data to receive full credit.

Day 3

Determine the effect of concentration on the rate of reaction. Conclusions must be supported with viable procedure and data to receive full credit.

Day 4

Each lab group will receive a time assignment at which their reaction must change color. Using insights gained from your previous days of experimenting you will design a procedure for your assigned time. This means you need to come to class prepared with your actual procedure to solve the problem of getting the reaction to change color at your assigned time. You may adjust this procedure for tomorrow’s assessment as you gather results.

Day 5

Lab Time Result / Grade % Earned
± listed seconds / 100
± listed + 2 / 94
± listed + 4 / 87
± listed + 6 / 84
± listed + 8 / 81
± listed + 10 / 78
± listed + 15 / 75
± listed + 20 / 71
± listed + 25 / 68
± listed + 30 / 66
± 1:00 min / 64
± 2:00 / 60
± no change / 50
± no set-up / 0

The final assessment. You will have 25 minutes to set up your reaction and make your final adjustments to your procedure. You may bring only two test tubes with you to the reaction vessels (50 mL beakers). Students will stand at their appointed time spot and on the word go, will begin the reaction. In order to get full points for your final,timed results, you must come within ±5 seconds of your assigned time. The following table is a tentative grading scale for the timed results.

STUDENT NOTES

  • Because of the stability of the solution over time, fresh material is made daily. This means that there may be slight variation in solution reactivity.
  • The idea of the lab write-up is to bring together the results of the experiment in a clear, concise way. Keep in mind that you are telling a story. The plot line is what you tried to do (methods), a summary of the outcome (data and calculations), and a comparison between theoretical values (if available) and your results, including an analysis of errors (results and discussion). Think about the lab experiment as a whole, re-read any materials that relate to the theory studied to get the big
    picture, and tell the story in a brief and concise manner.
  • Your report should explain the general approach used to solve the problem presented in the lab. Include instrumentation and techniques that are used to collect the data. Show the results of your experiment in a plot or table. Point out important features or trends. Discuss briefly how your result compares with theoretical concepts or with what you expected to find. Discuss briefly how errors in measurement or technique could have led to any discrepancies between theory and your results.

TITLE PAGE

PROBLEM

BACKGROUND/
METHODS

HYPOTHESIS

PROCEDURE

DATA

ANALYSIS

CONCLUSION

GENERAL APPEARANCE

Assessment Lab Score Sheet

  1. title
  2. date
  3. name
  4. period
  5. course
  1. in the form of a question
  2. addresses primary problem
  1. list of relevant scientific concepts included
  2. information needed to solve problem
  3. citations listed
  4. summary of lab research leading to final procedure
  1. in
  2. variable(s) tested included
  3. reasoning for hypothesis (because)
  4. based on design
  5. overall quality
  1. detailed material list
  2. step by step directions
  3. easily replicated
  4. appropriate safety procedures
  5. appropriate clean-up and disposal procedures
  6. overall quality
  1. tables are accurate and complete (scientifically appropriate)
  2. accurate, running account of observations
  3. adequate data collected
  4. overall quality
  1. complete sentences
  2. graphs are accurate and scientifically appropriate
  3. explanations of what data means
  4. sources of error discussed
  5. quantitative results of error
  6. evaluation of what was successful
  7. modifications to be made
  8. overall quality
  1. general statement about results
  2. compare hypothesis to results
  3. reasonable, chemistry based suggestion for further study
  4. overall quality
  1. format
  2. word-processed
  3. organized/clearly labeled sections
  4. all printed research is attached in appendix

TOTAL /100

1

1

1

1

1

1

2

2

2

2

10

1

2

1

2

2

2

2

2

1

1

4

4

2

4

4

1

2

4

4

2

2

2

10

1

1

2

2

2

2

2

3

Following is a generalrubric that may be helpful in writing your final report.

A. Title/Purpose: The student describes the overall purpose or goal of the experiment.

  • 4 - Succinctly states overall goal, by distilling and synthesizing information from the lab without including information about methods, data or other sections of the report. Has a reasonable title.
  • 3 - Less succinct, may contain some off topic statements but states an overall goal for the lab. Does not include information about methods, data or other sections of the report. Title may be inappropriate.
  • 2 - Verbose, lacks focus, echoes 'Approach' section of manual or includes methods, data etc. May have a poor or no title.
  • 1 - Verbose, does not reflect the actual purpose of the lab, contains specific steps or describes methods in detail. Poor or no title.
  • 0 - No section appears.

B. Background/Procedure: The student describes equipment, techniques, and theory used to achieve the purpose of the lab.

  • 4 - Succinctly describes the general approach to accomplishing the goal of the lab, as well as the functionality of any unique and necessary equipment or theoretical concept.
  • 3 - Less succinct, includes off topic statements, may not have described all equipment or theory adequately.
  • 2 - Verbose, lacks focus, echoes the 'approach' section of the manual; lists or discusses observations, calculations or results.
  • 1 - Rehashes the 'Approach' section of the manual, numbered lists of steps etc.; lists or discusses observations, calculations or results.
  • 0 - No section appears.

C. Data: Student summarizes, and presents data within the context of the experiment.

  • 4 - Neatly labels and logically organizes appropriate tables with all relevant and important data. Gives short description of table and data that put each in context of experiment, purpose and goals.
  • 3 - Data is tabulated, but may contain some organizational or logical lapses. All relevant and important data are shown and adequately described. Most data has a short description that puts it in context of the experiment, purpose and goals.
  • 2 - Data may not be tabulated, or just tables, with no supporting text appear. Poorly organized. Some data may be missing or not adequately described.
  • 1 - Data listed in step-by-step fashion, or is not listed at all. Important data is missing.
  • 0 - No section appears.

D. Calculations: The student applies appropriate chemical principals to the data to achieve the goals (purpose) of the lab. Note: calculations may or may not be appropriate for depending on the experimental methods.

  • 4 - Shows complete understanding of chemical concepts and principals, and mathematical techniques. Sample calculations appear in a logical sequence to achieve the purpose of the lab. Organized logically in plots or tables as appropriate. Uses appropriate chemical terminology and notation. Executes calculations correctly and completely.
  • 3 - Shows nearly complete understanding of chemical principals and mathematical techniques. Adequately and mostly logically organized with sample calculations to achieve purpose of lab. Uses mostly correct chemical and mathematical notation and terminology. Calculations are generally correct and complete, may contain some minor errors.
  • 2 - Shows limited understanding of chemical principals and mathematical techniques. Contains just a plot or table with no supporting text or sample calcs. Poorly organized with some incorrect chemical and mathematical notation. Inadequate sample calculations or calculations that do not achieve purpose of lab. May contain major computational errors or omissions in calculations.
  • 1 - Shows little or no understanding of chemical or mathematical principals. Misuses or fails to use correct chemical and mathematical notation. Inadequate or missing sample calculations. Contains major computational errors.
  • 0 - No section appears.

E. Analysis and Discussion: The student synthesizes, analyzes and interprets the results of the experiment.

  • 4 - The results are shown. Plots and/or tables serve to present result effectively, logically, and in an organized and succinct fashion. Important features and trends are noted. Results are thoroughly compared with purpose, expectations or theoretical calculations. Explains discrepancies between theory and results appropriately in terms of errors in measurement and technique. Demonstrates knowledge of content, chemistry, and purpose of experiment.
  • 3 - Results are shown, in plots and/or tables (where appropriate) that serve to present them in a logical, organized and succinct fashion. Points out nearly all important features and trends. Adequately compares results with expectations or theoretical calculations. Explains discrepancies between theory and results in terms of errors in measurement and technique but may contain some omissions or oversights. Demonstrates some knowledge of content, chemistry, and purpose of experiment.
  • 2 - Results are poorly presented, plotted or tabulated, or just a plot or table with no supporting text appears. Addresses few important features or trends. Explanations are verbose and unfocused. Comparison of results to theoretical results may not be included. Poor error analysis.
  • 1 - Results are not presented. No important features or trends are addressed. Poor or omitted error analysis. Lack of explanation or explanations are exceptionally verbose and unfocused.
  • 0 - No section appears.

Name Name

Day 1 Results

Investigation Summary

Day 2 Results

Investigation Summary

Data Collected

Initials/score

Day 3 Results

Procedure Summary

Results

Initials/score

Day 4 Results (changes made, methods used, data collected, WHAT ARE YOU DOING TOMORROW?, etc.)

Initials/score

Day 5 Results

Time Assigned Variable(s) Used

Actual Time

Briefly describe elements that helped or hindered final results.

All procedures used and data collected is our original work. At no time did we use other students enrolled (past or present) in Honors Chemistry as a source of information.

Student 1 SignatureStudent 2 Signature