Chemistry 141 Lab Let The Fun Begin Safety Rules Do not engage in horseplay in the lab at any time It will not be tolerated for any reason Do not perform any lab work without your instructor present This includes working on experiments using lab glassware and or using reagents and lab chemicals You may work on lab reports graphing or study in the lab without the instructor s presence In order to make up an experiment you must first obtain the approval of your instructor You must then obtain the permission of the instructor in whose lab you wish to work Finally you must inform the stockroom technicians Safety Rules You must wear approved eye protection at all times when anyone is doing lab work You must wear closed toe shoes not sandals to protect your feet against broken glass and spilled reagents We recommend that you wear a lab apron or old clothing In case of injury fire or other mishap inform the instructor at once If the instructor is not in the immediate area inform the chemistry technician in the stockroom Safety Rules Do not put anything in your mouth while in the lab You are not allowed to eat drink or smoke in the lab Use a fume hood in order to avoid prolonged contact with noxious vapors or poisonous gases Immediately use water to rinse off corrosive chemicals from your skin or eyes Notify an instructor Wash your hands before leaving the lab for the day Some chemicals can be readily absorbed through the skin Safety Rules Use a lubricant such as glycerine to insert glass tubing or a thermometer into a rubber stopper Hold the piece of glass which is being inserted or removed close to the end with a paper towel Clean up spills and breakage immediately Neutralize acids or base spills with sodium bicarbonate before washing down the area with water Safety Rules Familiarize yourself with the safety equipment in the lab including the first aid kit fire blanket fire extinguisher the safety shower and the eye wash station When heating the contents of a test tube point the open end of the tube away from everyone A vapor pocket may form beneath the surface of the contents and cause their ejection bumping Safety Rules Dispose of insoluble waste in the waste basket not in the sink Broken glass is to be disposed in the broken glass receptacle Be sure to read the labels on all chemical reagent containers before using their contents Using an improper reagent for an experiment can lead to a serious accident Safety Rules Do not take chemical reagent containers to your work bench Leave them at their initial location Do not use any of your lab equipment to dispense chemicals for an experiment The instructor will demonstrate the proper method for dispensing chemicals Chemicals are expensive items therefore transfer out only what you will need for the experiment Do not ever return used or excess chemicals to their original containers to prevent contamination Safety Rules At the conclusion of your lab period thoroughly clean up your work area Make sure that the gas to the bunsen burner is shut off Do not remove any chemicals or lab equipment from the laboratory 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 Lab Books 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 Luna Lovegood Experiment 1 Standard Deviation Lab Worked with Hermione Granger Lab Books Objective Why are you doing this experiment Reference the procedure and note any safety precautions Or if you used the Online Lab Manual Lehman J Olmstead T et al 2002 Experiment 2 Measuring Density using different types of Glassware Electronic version Grossmont College Chemistry 141 Laboratory Manual 5 10 Procedure Followed procedure outlined in the lab manual Lehman J Olmstead T et al 2002 Experiment 2 Measuring Density using different types of Glassware In Grossmont College Chemistry 141 Laboratory Manual 4th Edition pp 5 10 El Cajon California Safety Wear Safety glasses Lab Books Data and Observations This should be a log of what you saw along with any tables of data that may be necessary Trial Mass beaker water Mass beaker after pouring water out Mass Water delivered by beaker 1 2 3 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 Lab Books 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 No writeovers 375 788g 636 No obliterations 639 824g No Erasing Cross out once and rewrite 4 932g 5 382g Lab Books 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 Luna Lovegood 9 28 07 Severus Snape Potions Instructor Lab Reports 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 Title Page This will identify you your class and the experiment Very important so I can keep track of what you are handing in Standard Deviation Experiment Lab Luna Lovegood 25 Notebook Procedure 5 Data 15 Formal Report 75 Title Page Total Be sure to include the grading rubric 5 Signatures 5 Objecti ve 10 Introdu ction 15 Proced ure 5 Results and Calcul ations 15 Discus sion 15 Conclu sion 10 100 Chemistry 141 S Snape Section 5399 September 3 2007 Objective Why are you doing this experiment Objective To determine the accuracy and precision of laboratory glassware and to learn how a standard deviation is calculated To determine the density of some unknown liquids Introduction 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