Postlab 1 - Acid Base Titrations using pH meter.docx -...

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EXPERIMENT 1: ACID-BASE TITRATIONS USING A pHMETERAccuracy of EquipmentConstantsError AnalysisSignificant FiguresTotal Points = Earned Total 42.544.5Lab Data:The data you collected in lab may be entered in groups or as a single entry. Once a 'data group'opens up, enter data in every open text box before clicking the Submit button in the side panel. Once youSubmit and Confirm your lab data, click the Next Problem button to proceed down the page where you canenter answers to lab calculations, essays, balanced equations, and multiple choice questions. If you Submit/ Confirm incorrect data, you can correct your data with the Change Incorrect Data link at the top of thispage.Note: If you change / reset your data the program remembers any points you lost on calculations usingthe incorrect data and deducts those points from your total grade.Calculations: When you enter answers to calculations, you must pay attention to the tolerancesestablished by your Instructor which the program uses to grade your answer. If you are expected to roundyour answer to the correct number of Significant Figures, you will be notified in the side panel; otherwise,you need only enter a number that falls between the correct number minus the tolerance and the correctnumber plus the tolerance. The tolerance for any Chem21Labs calculation is found in the side panel onceyou open a calculation by clicking the Next Problem button. If the Tolerance is ± 2 in 3rdSF, it means that ifyour answer falls between the correct answer minus 2 in the 3rdSignificant Figure AND the correct answerplus 2 in the 3rdSignificant Figure, Chem21Labs will count it as correct. In this example, the '3rdSF' is theMINIMUM number of significant figures required for the answer. If the tolerance is not ± 0 in a certainSignificant Figure, it is recommended that you use two more Significant Figures than required as long asyour answer is within the range created by the tolerance. Enter only the number for Lab Data andCalculations - never the unit.Essays: short answers to questions can be entered at any time by clicking the Edit link associated with the
question. If you don't click the link, the essay editor will open automatically after clicking the Next Problembutton if it is next in the "sequence". If you "click ahead" in the lab to enter essay answers, the NextProblem button may not open a previous data box or calculation box - you can fix this by reloading thepage or clicking the Back to Main Menu link and clicking on the assignment again.To use scientific notation you will use the Enotation. For example, 4.5 x 10-3would be entered as 4.5E-3 or 4.5e-3.LAB DATADROP COUNTER CALIBRATIONDrop Counter calibration (drops/mL)24.0STRONG ACID / STRONG BASE TITRATIONIntital volume of strong acid (mL) This should be the volume of the stock solution, WITHOUT the extra water to cover the pH meter bulb.

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