Question

Calcium Oxide will react with ammonium chloride to produce ammonia gas, water vapor, and calcium chloride. If only 16.3 g of ammonia is produced from 112 g of calcium oxide and 224 g of ammonium chloride, what is the percent yield?

Answer 1

Answer:

                     %age Yield  =  22.72 %

Explanation:

                    The balance chemical equation is as follow;

                           2 NH₄Cl + CaO → 2 NH₃ + CaCl₂ + H₂O

Step 1: Calculate Moles of CaO, NH₄Cl and NH₃;

CaO:

        Moles  =  Mass / M.Mass

        Moles  =  112 g / 56.07 g/mol

        Moles  =  1.99 moles of CaO

NH₄Cl:

        Moles  =  Mass / M.Mass

        Moles  =  224 g / 53.49 g/mol

        Moles  =  4.18 moles of NH₄Cl

NH₃:

        Moles  =  Mass / M.Mass

        Moles  =  16.3 g / 17.03 g/mol

        Moles  =  0.95 moles of NH₃

Step 2: Calculate Limiting reagent as:

According to equation.

                   2 moles of NH₄Cl reacts with  =  1 mole of CaO

So,

              4.18 moles of NH₄Cl will react with  =  X moles of CaO

Solving for X,

                     X =  4.18 mol × 1 mol / 2 mol

                     X  =  2.09 mol of CaO

This means that none of the given reagent is limiting reagent. They both are almost equal in number of moles.

Step 3: Calculate Theoretical Yield of NH₃ as;

According to equation.

                   2 moles of NH₄Cl produced  =  2 moles of NH₃

So,

              4.18 moles of NH₄Cl will produce  =  X moles of NH₃

Solving for X,

                     X =  4.18 mol × 2 mol / 2 mol

                     X  =  4.18 mol of NH₃

Step 4: Calculate Percentage Yield as;

             %age Yield  =  Actual Yield / Theoretical Yield × 100

             %age Yield  =  0.95 mol / 4.18 × 100

             %age Yield  =  22.72 %