Question

In the experiment of Diels-Alder Reaction of Cyclopentadiene with Maleic Anhydride 0.1039 g of maleic acid, 0.40 mL of ethyl acetate, 0.40 mL of ligroin, and 0.10 mL of cyclopentadiene were used. The final mass of cis-norbornene-5,6-endo-dicarboxylic anhydride was 0.0277 g. What is the percent yield?

Answer 1

Molar mass of maleic anhydride = 98.06 g/mol

Mass of maleic anhydride used = 0.1039 g

Moles of maleic anhydride used = 0.1039/98.06 = 0.0011 mol

Molar mass of cyclopentadiene = 66.10 g/mol

Volume of cyclopentadiene used = 0.10 mL

Density of cyclopentadiene = 0.786 g/mL

Therefore, mass of cyclopentadiene used = 0.10 x 0.786 = 0.0786 g

Therefore moles of cyclopentadiene used = 0.0786/66.10 = 0.0012 mol

Moles of maleic anhydride used < moles of cyclopentadiene used

Therefore, maleic anhydride is the limiting reagent.

Theoretically, 1 mol maleic anhydride will produce 1 mol cis-norbornene-5,6-endo-dicarboxylic anhydride.

Therefore, theoretically, 0.0011 mol maleic anhydride will produce 0.0011 mol cis-norbornene-5,6-endo-dicarboxylic anhydride.

Molar mass of cis-norbornene-5,6-endo-dicarboxylic anhydride = 164.16 g/mol

Therefore theoretical yield of cis-norbornene-5,6-endo-dicarboxylic anhydride = 164.16 x 0.0011

                                                                                                                            = 0.181 g

Actual yield of cis-norbornene-5,6-endo-dicarboxylic anhydride = 0.0277 g

Now, percent yield = (actual yield x 100)/theoretical yield

                              = (0.0277 x 100)/0.181

                              = 15.30 %