Lab report for Experiment #2: Extraction
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Title: Experiment #2: Extraction
Purpose: What is the purpose of this lab? In your OWN words!
Weighed out 3.2568 grams of chemical mixture that was yellow in color.
Dissolved dry chemicals in 38 ml CH2Cl2 with gentle heating. Poured the yellow solution into sep funnel. Added 10 ml CH2Cl2 to flask to rinse, poured solution into sep funnel. Added 15 ml 3 M HCl, gently mixed and vented (saw bubbles during mixing, heard the evolution of gas while venting). Allowed layers to separate. Upper layer determined to be aqueous by density: lower layer removed. Upper layer placed into separate flask labeled “A” for acid extract. Lower layer placed into sep. funnel and reextracted with 15 ml 3 M HCl. Combined aqueous layers in flask A
Reextracted CH2Cl2 layer containg chemicals with 15 ml 3 M NaOH. Upper layer in flask labeled “B” for base extract. Re-extract organic layer with 15 ml 3M NaOH. Combined base extracted materials in flask “B”. Saw bubbles during mixing, heard the evolution of gas while venting.
Dried organic layer with anhyd. Na2SO4 until free flowing salt was observed (about 3 grams). Filtered the organic solution into a tared 100 ml round-bottom flask. Rinsed flask and funnel with 10 ml of CH2Cl2 and rotovaped off remaining solvent and weighed flask. The biphenyl obtained was white in color and was like a powder.
Weight of flask and biphenyl =
Weight of empty flask =
Weight of recovered biphenyl =
Cooled flask A in a water bath. Added 18 ml 6 M NaOH and pH tested. Still acidic, litmus paper was red. Added 1.5 ml more 6 M NaOH; and the alkaline solution became cloudy and pH paper turned blue. Yellow crystals were seen to form. Cooled in ice bath for 21 minutes. Collected p-nitroaniline (yellow crystals)using vacuum filtration. Washed with cold water and...
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