Chemistry 2e · 18.8 Occurrence, Preparation, and Properties of Phosphorus

Occurrence, Preparation, and Properties of Phosphorus: practice problems

6 problems from the book, with its answers. Check your working, or have any of them explained to you on the whiteboard.

1. Exercises 67

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

   (a) PH₃

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

   (c) P₂H₄

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

   (e) PF₅

   Show the book’s answerSign up free to have it checked

2. Exercises 69

   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) ${\text{P}}_4+{\text{F}}_2⟶$

   Show the book’s answerSign up free to have it checked

3. Exercises 71

   What volume of 0.200 M NaOH is necessary to neutralize the solution produced by dissolving 2.00 g of PCl₃ is an excess of water? Note that when H₃PO₃ is titrated under these conditions, only one proton of the acid molecule reacts.

   Show the book’s answerSign up free to have it checked

4. Exercises 73

   How many tons of Ca₃(PO₄)₂ are necessary to prepare 5.0 tons of phosphorus if the yield is 90%?

   Show the book’s answerSign up free to have it checked

5. Exercises 75

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

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

   (b) PF₅

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

   (d) POF₃

   Show the book’s answerSign up free to have it checked

6. Exercises 77

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

   (a) NaH₂PO₃

   (b) PF₅

   (c) P₄O₆

   (d) K₃PO₄

   (e) Na₃P

   (f) Na₄P₂O₇

   Show the book’s answerSign up free to have it checked