week 3: distillation i · column "a" is packed with 20% carbowax 20m on chromasorb p aw...
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![Page 1: Week 3: Distillation I · Column "A" is packed with 20% carbowax 20M on Chromasorb P AW DMCS, 80/100 mesh. Column "B" is packed with 20% DC-200 20M on Chromasorb P AW DMCS, 80/100](https://reader034.vdocument.in/reader034/viewer/2022042021/5e77e0571fddfb5b7f109044/html5/thumbnails/1.jpg)
!Week 3: Distillation I
Best way to separate a mixture of two liquids
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Simple Distillation
Simple Distillation = 1 evaporation / condensation
1 Simple Distillation = 1 Theoretical Plate
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Simple vs Fractional Distillation
1 Fractional Distillation = >1 Theoretical Plates
Fractional Distillation is more efficient than the
Simple Distillation.
Claisen condenser
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Record bp every 0.4 ml Continue recording bp every 0.4 ml until there is ~3ml left in the
round bottom flask.
Simple Distillation
14 ml mixture of acetone (bp = 56 oC)
and ethanol (bp = 78 oC)
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Record bp every 0.4 ml After 3 ml COLLECT 5 drops of
distillate in a clean and dry conical vial. (Seal vial; keep for GC)
Continue recording bp every 0.4 ml until there is ~3ml left in the round
bottom flask.
Fractional Distillation
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Graphing Your Data
1.0 52.2 52.2 52.3 52.4
1.2 1.6 1.8
8.0 ??
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Calculating Number of Theoretical Plates
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Gas Chromatography
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Calculating Number of Theoretical Plates
GC Chromatograph
1st Fraction
2nd Fraction
Acetone (bp = 56 oC)
Ethanol (bp = 78.5 oC) !
Acetone
Ethanol
Area % 68.6 Acetone 31.4 Ethanol
!Xa Ya
Xb, Yb will be provided by your TA i.e. Xb = 52, Yb = 48
! alpha= 1.7
n = [log (68.6/52) - log(31.4/48)] / log1.7 !
n = 1.35