# Lab 6 Calibration Methods and Introduction to UV.pdf - Lab...

• 6

This preview shows page 1 - 2 out of 6 pages.

Lab 6: Calibration Methods and Introduction to UV-Visible Spectroscopy Prelab Questions 1.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 volume of 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. Mass of solute: 1L x 100.0mg L = 100.0mg or .1000g ASA Final concentration of 2% ( v v ) HCL: 2mL HCL 100mL x 10mL (to make 1000mL) = 20mL HCl b. 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! Weigh out .1000g of ASA and transfer to a volumetric flask. Methanol is added to increase solubility, via swirling the solution. Add a small amount of DI water and continue swirling. Finally, 20.00mL of HCl, measured from a graduated cylinder, is slowly added before diluting to the mark with more DI water. Invert three times. 2. Create dilution tables to create your standards for the external calibration method given a 100.0 ppm solution and a 10.00 mL volumetric flask and a micropipette with a range from 100.0 to 1000. μL. Use C1V1=C2V2. Final Solution Concentration C2 Final solution
• • • 