Question

1. Stoichiometry question:  If you have a reaction that gives a 75% yield, how much product would you get if you add (for example:  3 g of vanillin + 3 mL of 10.6M acetic anhydride).
   • First, determine which is the limiting reactant.
   • Determine the molecular weight of the product.
   • Determine how much product can be produced theoretically.
   • Then, determine the actual yield when the reaction has a 75% yield.

Answer 1

In this reaction the vaniline is a limiting agent as the key starting material is vaniline and taken as 1 mole equivalent while acetic anhydride as a 3 ml 10.6 M solution which is 3.25 gm and used as 1.63 mole equivalent with vaniline.i.e excess.

Theoratically 3.83 gm product should be formed if recation completed 100%

As the reaction is 75% conversion we will get 2.872 gm of product.

this is for 100% yield.C8H8O3 =VANILINE . C4H6O3 = ACETIC ANHYDRIDE