please calculate the
1.theoretical yield,
2.percent yield, and
3. overall percent yield frombenzaldehyde.
my products weight was 2.137 g
experiment was \"Isolation ofTetraphenylcyclopentadienone, then Recrystalization ofTetraphenylcyclopentadienone\"
HERE IS MY PROTOCOL I FOLLOWED TO GET MASS OF2.137 g
THIS IS ALL AVAILABLE INFORMATION!!!
Add 1.5 g benzil, 1.5 g dibenzyl ketone, and 12 mL absoluteethanol to a 50-mL round-bottom flask. Place a magnetic stir bar inthe flask. Attach a condenser, having lightly greased the joint.Stir and heat the mixture at 70ºC (with the condenserrunning) until the solids dissolve. Then raise the temperatureto 80ºC with continued stirring. Using a 9\" Pasteur pipette, adddropwise 2.25 mL of ethanolic potassium hydroxide solution throughthe condenser into the flask; make an effort to prevent any dropsfrom contacting the condenser walls (each drop should falldirectly into the reaction mixture). The mixture willimmediately turn a dark purple. Once you have added the potassiumhydroxide, raise the temperature to about 85ºC. Stir the mixture atthis temperature for 15 minutes.
Isolation of Tetraphenylcyclopentadienone
At the end of the heating period, remove the flask from the heatand allow it to cool to room temperature. Then place the flask inan ice-water bath for 5 minutes to complete the crystallization ofthe product. Collect the deep purple crystals on a Büchner funnelby vacuum filtration. Wash the crystals with 3 4-mL portions ofice-cold 95% ethanol; this wash solvent should be used to transfercrystals from the round-bottom flask to the Büchner funnel if theydo not all come out when the mixture is initially poured into thefunnel. After air-drying the crystals for a few minutes, completethe drying in a 100ºC-oven for a few minutes.
RecrystallizingTetraphenylcyclopentadienone
Recrystallize your tetraphenylcyclopentadienone from a 1:1mixture of 95% ethanol and toluene; approximately 24 mL of thissolvent mixture will be required per gram oftetraphenylcyclopentadienone, but remember to only add the minimumboiling solvent necessary to dissolve the solute. Recover thecrystals by vacuum filtration (as above) and redeterminethe melting point.
Weigh the dried product and calculate the percent yield. Alsocalculate the overall percent yield from benzaldehyde. Determinethe melting point. If the melting point is not within 2ºC of theliterature value, you should recrystallize your product (seebelow).
