Question

In \[\ce{PO^{3-}4}\] ion the formal charge on the oxygen atom of P – O bond is ______.

Options

• + 1

• – 1

• – 0.75

• + 0.75

Answer 1

In \[\ce{PO^{3-}4}\] ion the formal charge on the oxygen atom of P – O bond is – 1.

Explanation:

Formal charge of the atom in the molecule or ion = (Number of valence electrons in free atom) – (Number of lone pair electrons + 1/2 Number of bonding electrons)

\[\ce{PO^{3-}4}\] :

\[\begin{array}{cc}
\ce{^-O}\\
\phantom{.....}\backslash\\
\phantom{.............}\ce{P = O}\\
\phantom{......}/\phantom{.}|\\
\phantom{.....}\ce{^-O}\phantom{..}\ce{O-}
\end{array}\]

For charge on oxygen = `6 - (6 + 1/2 xx 2) = 6 - 7 = - 1`