what is the correct lewis structure for pf3? n = 32, a = 26, s = 6, bonds = 3
what is the correct lewis structure for pf3? n = 32, a = 26, s = 6, bonds = 3
Answer
Explanation:
Step1: Determine valence - electrons
Phosphorus (P) has 5 valence electrons and each fluorine (F) has 7 valence electrons. So the total number of valence electrons ($A$) is $5 + 3\times7=26$.
Step2: Calculate the number of bonding electrons
The number of shared electrons ($S$) can be calculated using the formula. Here, the number of bonds is 3, and each bond has 2 electrons, so $S = 6$.
Step3: Distribute non - bonding electrons
The remaining electrons are used as non - bonding electrons on the atoms. Fluorine needs 8 electrons to complete its octet. After forming 3 P - F bonds, the remaining electrons are placed as lone pairs on the fluorine atoms and on the phosphorus atom. Each fluorine atom has 3 lone pairs and phosphorus has 1 lone pair.
Answer:
The first structure (left - most) is the correct Lewis structure for $PF_3$ as it shows 3 P - F bonds, each fluorine with 3 lone pairs and phosphorus with 1 lone pair, satisfying the octet rule for all atoms.