E5

docx

School

University of California, San Diego *

*We aren’t endorsed by this school

Course

43A

Subject

Chemistry

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by ChancellorMetalWombat6

NAME: Qiutong Huang EXPERIMENT 5 DISTILLATION AND GAS CHROMATOGRAPHY Summary of Points for Experiment 5: Item Possible Points Actual Points PRE-LAB 2 NOTEBOOK: Purpose/Table of Reagents 2 Corrections 2 Blank Spaces 2 Signatures 2 TLC’s N/A Coherent 2 Conclusions (absent here) 1 Sub-Total = 13 REPORT: Introduction 2 Data and Calculations 56 Data Analysis / Conclusions 5 Sub-Total = 63 TOTAL 76 POINT DEDUCTIONS: minus any page over 7 (0) minus for late reports (0) minus for TA points (0) minus for missing attachments (0) TOTAL POINTS 76 ADJUSTED TOTAL POINTS = Total Points x 60/76 60

INTRODUCTION (2 points) This experiment aimed to separate the compounds in mixture using fractional distillation which is based on the boiling point difference of different compound. Then, Gas Chromatography (GC) was employed to identify the compound isolated in the sample fraction and the data analysis of GC could be used to compare the efficiency of separation using fractional and simple distillation. Fractional distillation differs from simple distillation in that the condenser is packed with copper wires and is insulated, resulting purer distillate. GC is an analytic tool that is based on compound volatility to separate out compounds and compounds with lower boiling points will tend to move faster down the column which yield lower retention times. DATA AND CALCULATIONS FRACTIONAL DISTILLATION TEMPERATURE DATA (4 points; 0.1 point per data point) FRACTION #1 FRACTION #2 FRACTION #3 FRACTION #4 mL T ( o C) mL T ( o C) mL T ( o C) mL T ( o C) 1 68.0 1 70.0 1 71.5 1 76.0 2 68.9 2 70.0 2 71.5 2 77.0 3 69.0 3 70.0 3 71.5 3 77.0 4 69.2 4 71.0 4 72.0 4 78.0 5 69.2 5 71.0 5 73.0 5 78.0 6 69.2 6 71.0 6 73.0 6 78.0 7 69.5 7 71.0 7 73.0 7 79.0 8 69.8 8 71.0 8 74.0 8 79.0 9 69.8 9 71.0 9 75.0 9 79.0 10 69.8 10 71.0 10 76.0 10 78.0 FRACIONAL DISTILLATION GC DATA Enter the data obtained from GC analysis of the original and the 4 distillation fractions to the table below. (1 point; 0.1 point per data point) Fraction Component GC Peak Area original 50:50 (V:V) n-hexane 49562 original 50:50 (V:V) n-heptane 54315 1 n-hexane 78516 n-heptane 6222 2 n-hexane 60768 n-heptane 8016 3 n-hexane 59355 n-heptane 18471 4 n-hexane 62256 n-heptane 26601

SIMPLE DISTILLATION TEMPERATURE DATA FRACTION #1 FRACTION #2 FRACTION #3 FRACTION #4 mL T ( o C) mL T ( o C) mL T ( o C) mL T ( o C) 1 38.0 1 49.2 1 53.2 1 64.0 2 41.0 2 50.0 2 54.0 2 65.0 3 43.0 3 50.5 3 55.0 3 66.0 4 44.0 4 51.0 4 56.0 4 66.8 5 45.0 5 51.5 5 57.0 5 67.0 6 46.0 6 52.0 6 59.0 6 68.0 7 47.0 7 52.1 7 61.0 7 68.2 8 48.0 8 52.8 8 61.5 8 69.0 9 48.0 9 52.9 9 63.0 9 69.0 10 49.0 10 53.1 10 64.0 10 69.0 SIMPLE DISTILLATION GC DATA Consult the GC traces for the simple distillation (provided at the end of the Report Form Guide) and fill in the table below with the peak area data. (1 point; 0.1 point per data point) Fraction Component GC Peak Area original 50:50 (V:V) n-hexane 53559 original 50:50 (V:V) n-heptane 53268 1 n-hexane 69525 n-heptane 24549 2 n-hexane 65738 n-heptane 28408 3 n-hexane 61887 n-heptane 36915 4 n-hexane 47428 n-heptane 45532 GRAPH 1 Plot the distillation temperature as function of volume of distillate (data from the DISTILLATION TEMPERATURE DATA tables). Plot the data points for every 5 mL of distillate collected. (10 points; 5 points each curve)

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

0 5 10 15 20 25 30 35 40 45 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 Fractional Distil- lation Simple Distil- lation Distillate Volume (mL) Temperature (oC) CALCULATIONS (Midpoint Temperatures) Show work for calculation of midpoint temperature for the 8 fractions: (4 points; 0.5 points for each calculation) Fractional: #1 mid-temp=(68+69.8)/2=68.9 ≈ ℃ 69 ℃ #2 mid-temp=(70+71)/2=70.5 ≈ ℃ 71 ℃ #3 mid-temp=(71+76)/2=73.5 ≈ ℃ 74 ℃ #4 mid-temp=(76+78)/2=77 ℃ Simple: #1 mid-temp=(38+49)/2=43.5 ≈ ℃ 44 ℃ #2 mid-temp=(49.2+53.1)/2=51.2 ℃ #3 mid-temp=(53.2+64)/2=58.6 ≈ ℃ 59 ℃ #4 mid-temp=(64+69)/2=66.5 ≈ ℃ 67 ℃ CALCULATIONS (Mole Fractions) Show work for calculation of the 16 mole fractions: (16 points; 1 point for each calculation) Fractional Distillation: Relative response factor for component a=1/(49562/54315)=1.096 #1 : Corrected area for component a=78516*1.096=86046 mole of a=Volume*density/molecular weight= 86046 86046 + 6222 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.07086 mol; MF a = 0.07086/(0.07086+0.004573)=0.9394 mole of b=Volume*density/molecular weight= 6222 86046 + 6222 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.004573mol; MF b =1- MF a =0.06062 #2 : Corrected area for component a=60768*1.096=66596 mole of a=Volume*density/molecular weight= 66596 66596 + 8016 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.06782 mol; MF a = 0.06782/(0.06782+0.007285)=0.9030 mole of b=Volume*density/molecular weight= 66596 66596 + 8016 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.007285mol; MF b =1- MF a =0.0970

#3 : Corrected area for component a=59355*1.096=65047 mole of a=Volume*density/molecular weight= 65047 65047 + 18471 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.05918 mol; MF a = 0.05918/(0.05918+0.014996)=0.7978 mole of b=Volume*density/molecular weight= 18471 65047 + 18471 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.014996mol; MF b =1- MF a =0.2022 #4 : Corrected area for component a=62256*1.096=68226 mole of a=Volume*density/molecular weight= 68226 68226 + 26601 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.05467 mol; MF a = 0.05467 /(0.05467 +0.01902)=0.7419 mole of b=Volume*density/molecular weight= 26601 68226 + 26601 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.01902mol; MF b =1- MF a =0.2581 Simple Distillation: Relative response factor for component b=1/(53268/53559)=1.0055 #1 : Corrected area for component b=24549*1.0055=24683 mole of a=Volume*density/molecular weight= 69525 69525 + 24683 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.0561mol; MF a = 0.0561/(0.0561+0.0199)=0.738 mole of b=Volume*density/molecular weight= 24683 69525 + 24683 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.0199mol; MF b =1- MF a =0.262 #2 : Corrected area for component b=28408*1.0055=28563 mole of a=Volume*density/molecular weight= 65738 65738 + 28563 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.05297mol; MF a = 0.05297/(0.05297+0.02302)=0.697 mole of b=Volume*density/molecular weight= 28563 65738 + 28563 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.02302mol; MF b =1- MF a =0.303 #3 : Corrected area for component a=36915*1.0055=37117 mole of a=Volume*density/molecular weight= 61887 61887 + 37117 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.0475 mol; MF a = 0.0475 /(0.0475+0.0285)=0.625 mole of b=Volume*density/molecular weight= 37117 61887 + 37117 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.0285mol; MF b =1- MF a =0.375

#4 : Corrected area for component a=45532*1.0055=45781 mole of a=Volume*density/molecular weight= 47428 47428 + 45781 ∗ 10 mL ∗ 0.655 g / mL÷ 86.2 g / mol = 0.03866 mol; MF a = 0.03866 /(0.03866 +0.03732)=0.509 mole of b=Volume*density/molecular weight= 45781 47428 + 45781 ∗ 10 mL ∗ 0.6795 g / mL÷ 100.21 g / mol =0.03732mol; MF b =1- MF a =0.491 TABLE OF CALCULATED FRACTIONAL DISTILLATION DATA Fraction Component Mole Fraction Midpoint Temp 1 n-hexane 0.939 69 ℃ n-heptane 0.061 2 n-hexane 0.903 71 ℃ n-heptane 0.097 3 n-hexane 0.798 74 ℃ n-heptane 0.202 4 n-hexane 0.742 77 ℃ n-heptane 0.258

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

TABLE OF CALCULATED SIMPLE DISTILLATION DATA Fraction Component Mole Fraction Midpoint Temp 1 n-hexane 0.738 44 ℃ n-heptane 0.262 2 n-hexane 0.697 51.2 ℃ n-heptane 0.303 3 n-hexane 0.625 59 ℃ n-heptane 0.375 4 n-hexane 0.509 67 ℃ n-heptane 0.491 GRAPHS 2 and 3 (20 points; 10 points each graph) 68 69 70 71 72 73 74 75 76 77 78 0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000 Fractional Distillation n-hexane n-heptane Midpoint Temperature (oC) Mole Fraction 40 45 50 55 60 65 70 0.200 0.300 0.400 0.500 0.600 0.700 0.800 Simple Distillation n-hexane n-heptane Midpoint Temperature (oC) Mole Fraction

DATA ANALYSIS AND CONCLUSIONS (5 points) Based on the analysis of peak area for standard 50/50 volume mixture of hexane and heptane could be used to calculate relative response factor, which is further used in the calculation of mole fraction of compounds in sample fractions. The data collected from Gas Chromatography supported the fact that fractional distillation provides purer separation between compounds. For instance, fractional distillation had first fraction with 0.939 mol n- hexane to 0.061 mol n-heptane while simple fraction purest fraction was composed of 0.738 mol n-hexane to 0.262 mol n-heptane. ATTACHMENTS: GC TRACES Attach your GC chromatograms to this report. There should be a total of 5 GC traces (do NOT include the GC traces for the simple distillation). Below, record the GC instrument parameters: loss of 2 points for each missing GC parameter GC Parameters: Column packing material: 10% SE 30 LIQUID PHASE ON CHROMOSORB WHP SOLID SUPPORT, 80/100 MESH Helium air flow: 30mL/min Injector temperature: 130 ℃ Column temperature: 80 ℃ Detector temperature: 150 ℃ Detector current: 100 mA NOTE: For each missing GC trace (or unlabeled or incompletely labeled GC trace), 5 points will be deducted.

Heptane Heptane Fractional distillation Hexane/heptane Fraction #4 Fractional distillation Hexane/heptane Fraction #3 Fractional distillation Hexane/heptane Fraction #2 Fractional distillation Hexane/heptane Fraction #1 Heptane Heptane Heptane Hexane Hexane Hexane Hexane Hexane Fractional distillation Hexane/heptane starting material

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version