Problem 19b

Step 1.

The reactant one chose to compare is

 

To do this, one have to use the given weight of .

Then convert it to moles.

Then multiply it by its mole ratio, which is three moles of   is to two moles of  

 

Lastly, multiply it by the molar mass of  to get the needed mass of   to complete the reaction, i.e., 

 

 

   therefore,    is the limiting reactant

 

To determine the theoretical yield of the product, simply use the limiting reactant to determine the amount of product formed using stoichiometry.