Final answer:
To check the percent available phosphoric acid, titration with a base such as NaOH is used, while stoichiometry helps calculate the mass of phosphorus needed to produce a specific quantity of phosphoric acid considering the yield.
Step-by-step explanation:
To determine the percent available phosphoric acid (H3PO4), a common laboratory method is titration. Titration involves reacting a known concentration of a base, such as sodium hydroxide (NaOH), with the phosphoric acid solution until the reaction reaches an equivalence point, where the amount of acid equals the amount of base reacted. The titration curve for phosphoric acid, being a polyprotic acid, exhibits distinct equivalence points for each deprotonation step.
Regarding the production of phosphoric acid, the balanced equation for the preparation of phosphorus(V) oxide from phosphorus is:
And from phosphorus(V) oxide to phosphoric acid, the equation is:
To find the required mass of phosphorus to produce a certain amount of phosphoric acid with a given yield, you will need to use stoichiometry to calculate the theoretical yield first and then apply the percentage yield to find the actual amount needed. For the production of 1.00 × 104 kg of phosphoric acid with a 98.85% yield, this calculation would take into account the molar mass of phosphorus and the molar ratio from the balanced equation.