CHEM 162 Experiment Lab 4: Fractional Crystallization Part I: Fractional Crystallization of KNO3 with (NH4)2Fe(SO4)2.6H2O Impurity | 2023 Complete

CHEM 162 Experiment Lab 4: Fractional Crystallization Part I: Fractional Crystallization of KNO3 with (NH4)2Fe(SO4)2.6H2O Impurity | 2023 Complete. Starting Components (Fract. Crystallization #0) data entry 3 Step 3: Mixture before first crystallization 3 mass KNO3 4.501 g mass (NH4 )2Fe(SO4 )2 . 6H2O 0.501 g Total mass of the sample mixture 5.002 g % Impurity (i.e., % Fe compound in the mixture)* 10.02 % *(This is your % impurity for Fract. Crystallization # 0) Fract. Crystallization #1 Step 7: mass of dry filter paper + watch glass 30.8 g Step 10: mass of KNO3 crystals + filter paper + watch glass 32.95 g mass of KNO3 crystallized 2.140 g % KNO3 recovered (% of KNO3 in Step A.3.) 47.660 % 1 Step 11: mass of KNO3 crystals to be analyzed for purity in Part I.C 2.049 g B. Fract. Crystallization # 2 (Re-crystallization) Step 5: mass of dry filter paper + watch glass 30.48 g Step 7: mass of KNO3 crystals + filter paper + watch glass 30.685 g mass of KNO3 crystallized 0.205 g % KNO3 recovered (% of KNO3 in Step A.3.) 4.556 % 1 Step 8: mass of KNO3 crystals to be analyzed for purity in Part I.C 0.205 g Chem 162 - Experiment #4 I. Fractional Crystallization of KNO3 with (NH4 )2Fe(SO4 )2 ·6H2O Impurity II. The Solubility Curve of KNO3 DATA, CALCULATIONS, AND GRAPHS By signing below, you certify that you have not falsified data, that you have not plagiarized any part of this lab report, and that all calculations and responses other than the reporting of raw data are your own independent work. Failure to sign this declaration will result in 5 points being deducted from your report score. Signature: Note: All sections of this report, except the structural formulas, must be typed. Part I: Fractional Crystallization of KNO3 with (NH4 )2Fe(SO4 )2 .6H2O Impurity 1 C. Analysis to Determine % Impurity First Crystallization Step 3: Absorbance of the Fe(phen)3 2+ complex at 510 nm 0.89 2 What is your absorbance after dilution? (if applicable) N/A Multiply your absorbance by the dilution factor (if applicable) N/A Molar Absorptivity of ferroin, e 1.25E+04 M -1cm-1 Calculate the molarity of Fe2+ from the absorbance (pathlength = 1 cm) 7.12E-05 M 2 Volume of ferroin complex solution prepared in Steps C.1. and C.2. 0.0100 L Calculate the moles of Fe2+ (moles of Fe2+= moles of (NH4 )2Fe(SO4 )2 ·6H2O) 7.12E-07 moles 2 Calculate the molar mass (NH4 )2Fe(SO4 )2 ·6H2O 392.14 g/mole Calculate grams of (NH4 )2Fe(SO4 )2 ·6H2O in the crystals 2.79E-04 g 2 Mass KNO3 crystals analyzed for purity (from Step A.11.) (this cell will autofill from cell F41) 2.049 g Calculate % mass of (NH4 )2Fe(SO4 )2 ·6H2O in the crystals 1.36E-04 % (This is your % impurity for Fract. Crystallization # 1) 2 Does the absorbance exceed the desired range (0 to 2.0 A)? _____No_______ If so, what dilution factor did you use in order to get the absorbance in the desired range? ______N/A_____ Type your calculation for molarity of Fe2+ (1 mol ferroin = 1 mol Fe2+) Using Beer's Law: A=cbe c=A/be c= (0.89/1.25E4) = 7.12E-05M Fe2+ Type your calculation for moles of Fe2+ Molarity= Mol Solute/L Solution n= ML n= 0.010*(7.12E-05M) n=7.12E-07 moles of Fe2+ Type your calculation for grams of (NH 4 )2Fe(SO4 )2 ·6H2O n*(mm/1mol) = grams of (NH4 )2Fe(SO4 )2 ·6H2O 7.12E-07 * (392.14/1) = 2.79E-04 g of (NH4 )2 Fe(SO4 )2 ·6H2O