18.8 Occurrence, preparation, and properties of phosphorus  (Page 2/2)

Write the Lewis structure for each of the following. You may wish to review the chapter on chemical bonding and molecular geometry.

(a) PH ₃

(b) ${\text{PH}}_4{}^{+}$

(c) P ₂ H ₄

(d) ${\text{PO}}_4{}^{\mathrm{3-}}$

(e) PF ₅

Describe the molecular structure of each of the following molecules or ions listed. You may wish to review the chapter on chemical bonding and molecular geometry.

(a) PH ₃

(b) ${\text{PH}}_4{}^{+}$

(c) P ₂ H ₄

(d) ${\text{PO}}_4{}^{\mathrm{3-}}$

Complete and balance each of the following chemical equations. (In some cases, there may be more than one correct answer.)

(a) ${\text{P}}_4+\text{Al}⟶$

(b) ${\text{P}}_4+\text{Na}⟶$

(c) ${\text{P}}_4+{\text{F}}_2⟶$

(d) ${\text{P}}_4+{\text{Cl}}_2⟶$

(e) ${\text{P}}_4+{\text{O}}_2⟶$

(f) ${\text{P}}_4{\text{O}}_6+{\text{O}}_2⟶$

Describe the hybridization of phosphorus in each of the following compounds: P ₄ O ₁₀ , P ₄ O ₆ , PH ₄ I (an ionic compound), PBr ₃ , H ₃ PO ₄ , H ₃ PO ₃ , PH ₃ , and P ₂ H ₄ . You may wish to review the chapter on advanced theories of covalent bonding.

What volume of 0.200 M NaOH is necessary to neutralize the solution produced by dissolving 2.00 g of PCl ₃ is an excess of water? Note that when H ₃ PO ₃ is titrated under these conditions, only one proton of the acid molecule reacts.

How much POCl ₃ can form from 25.0 g of PCl ₅ and the appropriate amount of H ₂ O?

How many tons of Ca ₃ (PO ₄ ) ₂ are necessary to prepare 5.0 tons of phosphorus if the yield is 90%?

Write equations showing the stepwise ionization of phosphorous acid.

Draw the Lewis structures and describe the geometry for the following:

(a) ${\text{PF}}_4{}^{+}$

(b) PF ₅

(c) ${\text{PF}}_6{}^{-}$

(d) POF ₃

Why does phosphorous acid form only two series of salts, even though the molecule contains three hydrogen atoms?

Assign an oxidation state to phosphorus in each of the following:

(a) NaH ₂ PO ₃

(b) PF ₅

(c) P ₄ O ₆

(d) K ₃ PO ₄

(e) Na ₃ P

(f) Na ₄ P ₂ O ₇

Phosphoric acid, one of the acids used in some cola drinks, is produced by the reaction of phosphorus(V) oxide, an acidic oxide, with water. Phosphorus(V) oxide is prepared by the combustion of phosphorus.

(a) Write the empirical formula of phosphorus(V) oxide.

(b) What is the molecular formula of phosphorus(V) oxide if the molar mass is about 280.

(c) Write balanced equations for the production of phosphorus(V) oxide and phosphoric acid.

(d) Determine the mass of phosphorus required to make 1.00 $\times$ 10 ⁴ kg of phosphoric acid, assuming a yield of 98.85%.