Chem Homework conxlusion

Overview

You will conduct a conclusion using the two lab instructions provided below. This is an example of a perfect conclusion:

Example: The experiment evaluated the accuracy and precision of three types of glassware—150-mL beaker, 125-mL Erlenmeyer flask, and 50-mL graduated cylinder—when measuring 50 mL of water. The results indicated that the graduated cylinder provided the most accurate measurement, with an average measured volume of 50.332 mL, closest to the target value of 50 mL. Additionally, the graduated cylinder exhibited the best precision, with an average deviation of only 0.042 g from the mean mass. Conversely, the beaker demonstrated lower accuracy, with an average measured volume of 47.153 mL, and lower precision, as evidenced by its higher average deviation of 1.243 g. The Erlenmeyer flask also showed suboptimal accuracy and precision compared to the graduated cylinder, with an average measured volume of 47.941 mL and an average deviation of 1.604 g. The greater error of the flask and the beaker compared to the graduated cylinder is likely due to the graduated cylinder having more precise markings. The less precise markings on the flask and the beaker would make it equally possible to have too much or too little water, which would have made the deviations larger but would not necessarily change the average. However, the average volumes for the flask and the beaker were noticeably lower than the target of 50 mL, so there is probably another source of error. It is possible the meniscus was observed at the wrong height, which would systematically affect measured volumes. In applications where high accuracy and precision are not critical, such as tasks requiring approximately 50 mL of liquid within a range of 40–60 mL, the beaker offers the advantage of speed and simplicity. However, for tasks requiring greater precision, the graduated cylinder is the preferred choice.

- The Conclusion paragraph should address both Exp. 3 and 4 results, error, etc.

Rubric:

Conclusion: Paragraph	10 pts Conclusion in paragraph form 0 pts Conclusion not in paragraph form	/ 10 pts
Conclusion: Data	10 pts Primary results only Only the final numbers that speak directly to the motivation 5 pts Too much data e.g., intermediate values or raw data needed only for calculations 0 pts Primary results are missing	/ 10 pts
Conclusion: Interpretation	10 pts Explanation of results follows from data 0 pts Explanation of results disagrees with data	/ 10 pts
Conclusion: Motivation	10 pts Motivation addressed Reason or purpose for the question being answered in this lab, not just the question itself. 0 pts Motivation not addressed	/ 10 pts
Conclusion: Error	10 pts Specific probable (or known) error addressed Known error (based on direct observations) is best, but likely errors are acceptable 5 pts Specific error(s) addressed, but only unlikely error e.g., blaming prep workers or manufacturers 0 pts No error, or error is overly vague e.g., "human error" or "mistakes could have been made"	/ 10 pts