Question

which of the following is the formal charge on pcl₅? (reference p 226 of your textbook.) a 1 b 0 c 2 d -1

Explanation:

Step1: Recall the formula for formal charge

The formula for formal charge is \(FC = V - N - \frac{B}{2}\), where \(V\) is the number of valence electrons of the atom in isolation, \(N\) is the number of non - bonding electrons, and \(B\) is the number of bonding electrons. For \(PCl_{5}\), the central atom is \(P\). Phosphorus (\(P\)) has \(V = 5\) valence electrons. In \(PCl_{5}\), \(P\) forms 5 single bonds with \(Cl\) atoms. So \(B=10\) (since each single bond has 2 electrons) and \(N = 0\) (no non - bonding electrons on \(P\)).

Step2: Calculate the formal charge

Substitute the values into the formula: \(FC=5 - 0-\frac{10}{2}\). First, calculate \(\frac{10}{2}=5\). Then \(FC = 5 - 0 - 5=0\).

Answer:

B. 0