Question

if 334.6 g of phosphoric acid is reacted with excess potassium hydroxide. the final mass K3PO4 produced is found to be 248g. what is the percent yield?

Answer 1

Answer:

                     %age Yield  =  34.21 %

Explanation:

                   The balance chemical equation for the decomposition of KClO₃ is as follow;

                            3 KOH + H₃PO₄ → K₃PO₄ + 3 H₂O

Step 1: Calculate moles of H₃PO₄ as;

Moles = Mass / M/Mass

Moles = 334.6 g / 97.99 g/mol

Moles = 3.414 moles

Step 2: Find moles of K₃PO₄ as;

According to equation,

                 1 moles of H₃PO₄ produces  =  1 moles of K₃PO₄

So,

              3.414 moles of H₃PO₄ will produce  =  X moles of K₃PO₄

Solving for X,

                      X = 1 mol × 3.414 mol / 1 mol

                      X = 3.414 mol of K₃PO₄

Step 3: Calculate Theoretical yield of K₃PO₄ as,

Mass = Moles × M.Mass

Mass = 3.414 mol × 212.26 g/mol

Mass = 724.79 g of K₃PO₄

Also,

%age Yield  =  Actual Yield / Theoretical Yield × 100

%age Yield  =  248 g / 724.79 × 100

%age Yield  =  34.21 %