Which of the following statements correctly describes the Lewis dot structure of the neutral compound PCl_5?

• A. Phosphorus is surrounded by four chlorine atoms, each forming a single bond, and phosphorus has one lone pair.
• B. Phosphorus is surrounded by five chlorine atoms, each forming a single bond, and phosphorus has no lone pairs.
• C. Phosphorus is surrounded by three chlorine atoms, each forming a single bond, and phosphorus has two lone pairs.
• D. Phosphorus is surrounded by five chlorine atoms, each forming a double bond, and phosphorus has no lone pairs.

Answer: (B)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons available for bonding in PCl_5. Phosphorus (P) is in group 15 and has 5 valence electrons, and each chlorine (Cl) atom is in group 17 with 7 valence electrons. Since there are 5 chlorine atoms, calculate the total valence electrons as: \$5 + 5 \times 7$.
2. Step 2: Recognize that PCl_5 is a neutral molecule, so the total number of valence electrons calculated will be used to form bonds and lone pairs without any charge adjustments.
3. Step 3: Draw the skeletal structure with phosphorus as the central atom bonded to five chlorine atoms. Since phosphorus can expand its octet (being in period 3), it can accommodate more than 8 electrons.
4. Step 4: Assign single bonds between phosphorus and each chlorine atom. Each single bond accounts for 2 electrons, so 5 single bonds use \$5 \times 2 = 10$ electrons.
5. Step 5: Distribute the remaining electrons as lone pairs on the chlorine atoms to complete their octets. Since phosphorus uses all its valence electrons in bonding, it has no lone pairs. Confirm that phosphorus is surrounded by five chlorine atoms with single bonds and no lone pairs.