Benzoin to Hexaphenylbenzene lab questions.

Benzoin to Hexaphenylbenzene

There are 4 questions to answer.

Please determine the percentage yield for each of the three steps in the reaction and determine the overall percent recovery for the three step process.

The data is as follows:

In the 1st step of the synthesis benzoin is oxidized to benzil.

Add 0.25 millimoles of copper II acetate monohydrate and 0.013 moles of ammonium nitrate to a flask containing 3.5 mL of water. Warn the mixture. Cool the mixture then add 14 mL of glacial acetic acid and 0.014 moles of benzoin to the flask. Reflux the mixture then cool the mixture. Add 15 g of ice to the mixture then recyrstalize the crude product.

Question 1 The weight of the product (benzil) for this part of the reaction was 2.03 g. What is the percentage yield?

In the second step the benzil under goes aldol condensation to form tetraphenylcyclopentadienone.
Dissolve0.16 grams of KOH in 25 mL of ethanol add 6.0 milimoles of benzil followed by 6.0 millimoles of diphenyl acetone. Reflux then cool the vacuum filter to collect the tetracyclopentadienone product. Wash the product with 8 mL of cold water then 8 mL of ethanol.

Question 2 The weight of the product (tetraphenylcyclopentadienone) for this part of the reaction was 2.34 g. What is the percentage yield?

In the third and final step tetraphenylcyclopentadienone and diphenyl acetylene are refluxed and the final product is hexaphenlybenzene.
Add 1.3 millimoles of tetraphenylcyclopentadienone and 1.8 millimoles of diphenyl acetylene to a test tube. Heat the mixture and allow the mixture to reflux. Cool the mixture and add 5 mL of petroleum ether. Warm the mixture then cool the mixture collect the product (Hexaphenylbenzene) by vacuum filtration.

Question 3 The weight of the product (Hexaphenylbenzene) for this part of the reaction was 2.04 g. What is the percentage yield?

Question 4 What is the overall percent recovery for the three step process?