100%(13)13 out of 13 people found this document helpful
This preview shows page 1 - 4 out of 8 pages.
The preview shows page 2 - 4 out of 8 pages.
Experiment 34: An Equilibrium ConstantVarun AndrewsPooja PatelGeneral Chemistry (DAI)Professor Arthur SikoraKrina Patel3/28/2019
Hypothesis:The equilibrium constant for the equation,Fe3+(aq) + SCN(aq) FeNCS2+(aq),can bedetermined through the collection of the absorbance values of five different solutions withvarious concentrations of Fe (NO3)3,NaSCN, and HNO3.Materials and Methods:Please refer to Experiment 34 on pages 387-398 of Laboratory Manual for Principles of GeneralChemistry by J.A. Beran (10thEd.). Deviations from the published procedure are:1.We did not graph the Absorbance versus FeNCS2+on linear graph paper. Wegraphed on Excel after the procedure was completed.Results:In this table the molar concentration of Fe (NO3)3and NaSCN are shown.AA Set of Standard Solutions to Establisha Standardization CurveMolar Concentration of Fe (NO3)3(mol/L)0.2(~0.2M)Molar Concentration of NaSCN(mol/L)0.001(~0.001M)Data Plot appears below and onSheet 2StandardSolutionsBlank123451Volume of NaSCN (mL)0.001.002.003.004.005.002Moles of SCN-(mol)0.00E+001.00E-062.00E-063.00E-064.00E-065.00E-063[SCN-] (25 mL) (mol/L)0.00E+004.00E-058.00E-051.20E-041.60E-042.00E-044[FeNCS2+] (mol/L)0.00E+004.00E-058.00E-051.20E-041.60E-042.00E-045Percent Transmittance, %T10094.68270.358.351.96Absorbance,A00.0240.0860.1530.2340.285In this table the absorbance values of the first 5 standard solutions that were made were testedand recorded.B. Absorbance for the Set of Test Solutions
TestSolutions6789101Volume of Fe (NO3)3(mL)5.005.005.005.005.002Moles of Fe3+, initial (mol)1.00E-051.00E-051.00E-051.00E-051.00E-053Volume of NaSCN (mL)1.002.003.004.005.004Moles of SCN-, initial (mol)2.00E-064.00E-066.00E-068.00E-061.00E-055Percent Transmittance, %T97.187.58374.869.56Absorbance,A0.0130.0580.0810.1260.158Molar Concentration of Fe (NO3)3(mol/L)0.002(~0.002M)Molar Concentration of NaSCN (mol/L)0.002(~0.002M)This table shows the molar concentration of Fe (NO3)3and NaSCN.This table shows the absorbance values of the 5 test solutions that were produced as well as themoles of Fe3+and SCN-..