Which of the following best describes the Lewis dot structure of a neutral PCl_3 molecule?

• A. Phosphorus is at the center with three single bonds to chlorine atoms and one lone pair on phosphorus.
• B. Phosphorus is at the center with three double bonds to chlorine atoms and no lone pairs on phosphorus.
• C. Phosphorus is at the center with three single bonds to chlorine atoms and no lone pairs on phosphorus.
• D. Phosphorus is at the center with three single bonds to chlorine atoms and one lone pair on each chlorine atom.

Answer: (A)

Verified step by step guidance

1. Step 1: Identify the total number of valence electrons available for the molecule. 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 three chlorine atoms, calculate the total valence electrons as \$5 + 3 \times 7$.
2. Step 2: Determine the central atom, which is usually the least electronegative element. In PCl\(_3\), phosphorus is less electronegative than chlorine, so phosphorus will be the central atom.
3. Step 3: Draw single bonds between the central phosphorus atom and each of the three chlorine atoms. Each single bond represents 2 electrons shared between atoms.
4. Step 4: Distribute the remaining valence electrons to satisfy the octet rule for the chlorine atoms first, placing lone pairs on each chlorine to complete their octets.
5. Step 5: Place any leftover electrons on the central phosphorus atom as lone pairs. Check that phosphorus has a total of 8 electrons around it (including bonding and lone pairs) to satisfy the octet rule.