Chemistry 141 Lab

1. Chemistry 141 Lab

2. Lab Books • Get a lab book with prenumbered carbonless copy pages. Write your name on the front of the lab book. • All data in the lab book must be written in ink. • Do not tear any original pages out of the book, unless you are turning them in!!

3. Begin each lab with a title Enter the date you are beginning the experiment, your name, and list any lab partners you may be working with. Everyone will do the entire lab on their own, but you may want to work with someone else to compare your results August 20, 2007 Jane Doe Experiment 1 – Standard Deviation Lab Worked with Frank Smith Lab Books

4. Write the objective of the experiment. Why are you doing this experiment? Objective: To determine the accuracy and precision of glassware and to calculate the standard deviation. Lab Books

5. Reference the procedure and note any safety precautions. Procedure: Followed procedure outlined in the handout provided in lab. Dirbas, J. (2007). “Chemistry 141: Standard Deviation: Measurement of Volumes Delivered” [Handout 2007], Grossmont College, El Cajon, California. Safety: Wear Safety glasses Lab Books

6. Lab Books • Data and Observations • This should be a log of what you saw along with any tables of data that may be necessary • Be sure to draw and label the equipment used. I filled the beaker to the 50 mL line with an eyedropper. It was very difficult to determine when the water level reached the line on the beaker.

7. No writeovers 375.788g No obliterations 639.824g No Erasing Cross out once and rewrite. 4.932g 5.382g Be sure to write all data in your lab book in black or blue ink when you take the data. The only exception will be for data collected by the computer. Any data recorded on stray pieces of paper will be confiscated! Lab Books 636

8. At the end of the lab period, sign and date your lab book after your last data entry and get an instructor stamp. Copper sulfide precipitate was filtered and left in lab drawer to dry. The precipitate was a very fine black powder. Jane Doe 9/28/07 BeN FrON Instructor Lab Books

9. Typewritten reports documenting your experimental results. Some reports will be abbreviated as noted in write-up instructions. Be sure to clearly label each section! Title Page Objective Introduction Procedure Results and Calculations Discussion Conclusion Questions Lab Reports

10. This will identify the experiment, you, the course, your class, your instructor, and the date(s) the experiment was performed. Very important so I can keep track of what you are handing in! Be sure to include the grading rubric. Standard Deviation Experiment Jane Doe Lab Partner: (if appropriate) Chemistry 141 Section 5399 Instructor: BeN FrON September 3, 2007 completed September 7, 2007 turned in Title Page

11. Restate objective from lab book, but make sure to update it to make it more specific is something was left out. Objective: To determine the accuracy and precision of laboratory glassware and to learn how a standard deviation is calculated. Objective

12. This section tells a little bit about the theory of the experiment and how it will be done. Introduction: When doing scientific experiments it is always necessary to minimize the error where possible. Unfortunately, however, it is impossible to completely avoid error. In experiments there are several types of error. They are random error, systematic error, and gross error. Random error is--- Introduction

13. Reference the procedure used and note any deviations from the published procedure. Procedure Followed procedure from handout Dirbas, J. (2007). “Chemistry 141: Standard Deviation: Measurement of Volumes Delivered” [Handout 2007], Grossmont College, El Cajon, California. In this experiment the liquid used for the density determinations was an isopropanol/water mixture. Procedure

14. Results and Calculations • Tabulate data and any calculated values. Show sample calculations. (These may be hand written.) • For non numerical labs, summarize the data generated. Results and Calculations Sample Calculation for mass liquid xxx.xxg-xx.xxg=xx.xxg

15. This is where you get to explain your results Discussion: The average mass of water held by the beaker was 43.2g. This was less than expected based on the marking on the beaker. The mass of water held was probably low because I filled my beaker to the bottom of the line and it may have been designed to fill to the top of the line. I also noticed that--- Discussion

16. This is where you give the final result and evaluate your objective. This is essentially the punch line-- Conclusion The beaker held 53.4 grams of water with a standard deviation of 0.7 g. The graduated cylinder held 10.2 grams of water with a standard deviation of 0.1 g. Conclusion

17. Questions • Answer any questions posed in the lab here.

18. Experiment • You will measure the mass of water delivered by a beaker and by a graduated cylinder multiple times and determine the mass of water delivered with each instrument and the standard deviation. Results will be entered on the spreadsheet at www.grossmont.edu/dianavance

19. Sample Data Table Temperature of water_______________ Density of water at measured temperature_________ Balance used ______________________