Lab 5 - Calibration Methods and Introduction to UVVIS (4) -...

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Lab 5 Calibration Methods and Introduction to UV-Visible SpectroscopyThe lab is to be done in pairs, but the report is an individual Work.Type your responses to all questions and embed excel data tables and graphs into one single word document. Before coming to lab: Review Section 4.8 and Chapter 5, Calibration Methods. Read this lab handout. The more time you spend figuring out your dilutions and “recipes” the less time you will have to spend in the lab.Learning Outcomes: Students will apply external standard and standard addition calibration methods to solve the concentration of an unknown (assessed in “Results andDiscussion”-questions 5, 6). Students will understand the differences and uses of external standards, internal standards, and standard addition (assessed in “Results and Discussion”-question 8). Students will demonstrate mastery of Microsoft Excel for analysis of laboratory data (assessed in “Results and Discussion”-questions 1-4, 7).SDS: methanol, acetylsalicylic acidMaterials1000 mL volumetric flaskone 10-mL volumetric flasks per group. p-1000 micropipettes and tipsConcentrated HClMortar and pestleMethanol250 mL storage bottles for the 2 v/v% HClAcetylsalicylic Acid (pure powder)Aspirin Tablets (unknowns)UV-Vis spectrometer set to 236 nmTest tubes and test tube racksPrelab Questions1.a. (5) You will create 1.000L of 100.0 ppm stock solution of Acetylsalicylic acid (ASA,from the pure powder) in a 2 (v/v) % HCl in this lab. 2 (v/v) % HCl means the volumeof concentrated HCl and the volume of the diluted HCl is 2:100. Determine the mass of the solute and volume of conc. HCl you are going to weigh out or measure with a graduated cylinder. Show your calculation. b. (5) Describe exactly how you will make the 1.000 L of 100.0 ppm ASA. When this is weighed out, you must get the mass you have found exactly!2.(5) Create dilution tables to create your standards for the external calibration methodgiven a 100.0 ppm solution and a 10.00 mL volumetric flask and a micropipet with a range from 100.0 to 1000. µL. Use C1V1=C2V23..

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