Question

0.8002 g of (E)-cinnamic acid, 10 mL of glacial acetic acid and 1.7610g of pyridinium tribromide was heated under reflux to demonstrate the bromination of (E)-cinnamic acid. The mass of the final product was 3.4143 g and the melting point range was 175.4-203.4 ℃.

What is the theoretical yield, actual yield, percent yield? Please show work! (Pyridinium tribromide and cinnamic reaction react in a 1:1 ratio).

Answer 1

0.8002 g of (E)-cinnamic acid, 10 mL of glacial acetic acid and 1.7610g of pyridinium tribromide was heated under reflux to demonstrate the bromination of (E)-cinnamic acid. The mass of the final product was 3.4143 g and the melting point range was 175.4-203.4? What is the theoretical yield, actual yield, percent yield? Please show work! (Pyridinium tribromi de and cinnamic reacti on react in a 1:1 ratio) Но но Br www NH Br3 glacial acetic acid Br pyridinium tribromide (E)-Cinnamic acid (E)-Dibromocinnamic acid Mol. Wt: 319.82 Mol. Wt.: 148.16 Mo. Wt: 307.97 1.7610g 0.0055 mole 0.8002 g 0.0054 mole Here, cinnamic acid is the limiting reagent which is consumed fully after the reacti on So, 0.8002 g or 0.0054 mole of (E)-Cinnamic acid react with 0.0054 mole of pyridinium tribromide to afford 0.0054 mole of brominati on product (E)-Dibromocinnamic acid So, theoriti cal yield = 0.0054 mole of(E)-Dibromocinnamic acid (0.0054 x 307.97) g of product 1.663 g of product Whereas actual yield reported is 3.4143 g of product which is not possible That means product is impure and needs to be crystallize properly and pure product has m.p of 202-204°C. Percent yield(Actual yield / The oritical yield) x 100