Question

Phosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide: P4(l)+5O2(g-2 P20s(g) In the second step, diphosphorus pentoxide and water react to form phosphoric acld P20(9)+3 H200 2H,PO40) Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water.

Answer 1

Answer:

P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)

Explanation:

Phosphoric acid is synthesized using a two-step thermal process.

In the first step, phosphorus and oxygen react to form diphosphorus pentoxide. The corresponding chemical equation is:

P₄(l) + 5 O₂(g) ⇒ 2 P₂O₅(g)

In the second step, diphosphorus pentoxide and water react to form phosphoric acid. The corresponding chemical equation is:

P₂O₅(g) + 3 H₂O(l) ⇒ 2 H₃PO₄(aq)

We can get the net chemical equation by adding the first step, the second step multiplied by 2, and canceling what is repeated on both sides.

P₄(l) + 5 O₂(g) + 2 P₂O₅(g) + 6 H₂O(l) ⇒ 2 P₂O₅(g) + 4 H₃PO₄(aq)

P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)