Question

Reaction is Diels-Alder Reaction:

0.6 g (Anthracene) + 0.3 g (maleic anhydride) --> product [9,10-dihydroanthreceno-9,10-endo- α, β-succinic anhydride] 0.70 grams obtained.

When vacuumed, xylened and isolated, the product yielded 0.70 grams product.

Please show how to calculate % yield with the weights above (Theoretical + Actual).

Answer 1

The given reaction is a cyclo addition reaction between diene and a dienophile.Here anthracene acts as diene and Maleic anhydride acts as dienophiile .The reactions are expressed as follows;

Dials Aldu Nacios + 1 Diene Dienophi la - 9,10-,-Succinic antydrde nthasis t 9, 10- dihyeleoanthra cno + Anthsaer Maleic Addut

Theorectical and percentage yield are calculated as follows;

Limiting reagent;

One mole of anthracene is 178.23 gms

0.6gms of anthracene is 0.0033 moles

One mole of maleic anhydride  is 98.06 gms

0.3 gms of maleic anhydride is 0.0030 moles

As the number of moles reacting is less for maleic anhydride it functions as limiting reagent Theoretical Yield

One mole of maleic anhydride gives one mole of the adduct

ie. 98.06 gms of maleic anhydride gives 276.29 gms of the adduct

So 0.3 gms of maleic anhydride gives 276.2/ 98.06 * 0.3. =0.85 gms of adduct

Percentage yield

Actual yield/Theoretical yield* 100 = 0.7/ 0.85 *100 = 82.35%