Question

In $PO_{4}^{3-}$ ion, the formal charge on each oxygen atom and $P-O$ bond order respectively are :

• A. -0.75, 1.25
• B. -0.75, 1.0
• C. -0.75, 0.6
• D. -3.1, 25

Answer 1

Answer: (A)

-0.75, 1.25

Answer 2

Average formal charge on each of the oxygen atom rs calculated as follows :
(i) Total number of electrons present in valence shell of $(P-0)=5+8=13$
(ii) Total number of electrons involved in bond formation $=13-3=10$
(iii) Number of bonds in $P O_{4}^{3-}$ ion $=\frac{10}{2}=5$
(iv) Average P-0 bond order $=\frac{5}{4}=1.25$
(v) Average formal charge on each 'O' atom
$=\frac{\text { total charge }}{\text { total entity of }^{\prime} O^{\prime} \text { atom }}$
$=-\frac{3}{4}=-0.75$