Question

this is from the lab Spectrophometric determination of Aspirin content of tablets. How do find the concentration using beers law?

CUI Dele t on Aspirin Content Determination of ASA Content of Tablets Lab Report You have entered the following experimental values: Mass of pure acetylsalicylic acid (ASA) : 0.519 g Dilution 2:11 4:11 6:11 8:11 10:11 Absorbance (a.u.) 0.119 0.239 0.344 0.470 0.564 Mass of tablet : 0.3589 Absorbance read on the Spectrovis Plus : 0.282 a.u. The questions below are part of the final analysis; they are due at the beginning of the next lab, Mon Oct 28 15: Analysis of the standard solutions: Calculate the number of moles of ASA: 0.00288 You are correct. Your receipt no. is 157-2612 Previous Tries Calculate the molar concentration of the 250 ml solution of ASA: 0.0115 You are correct. Your receipt no is 157-4145 Previous Tries Calculate the molar concentration of the 100 ml solution of ASA: 0.00115 MacBook Pro

Answer 1

1) Moles = mass/molar mass

= 0.519/180 = 0.00288 g/mol

2) Molar concentration = moles×1000/volume (in ml)

= 0.00288×1000/250

= 0.0115 M