In $\mathrm{PO}_{4}^{3-},$ the formal charge on each oxygen atom and the $\mathrm{P}-\mathrm{O}$ bond order respectively are

• A

  -0.75,0.6
• B

  -0.75,1.0
• Correct answer
  C

  -0.75,1.25
• D

  -3,1.25

Solution

Bond order $=\frac{\text { Number of bonds }}{\text { Number of Resonating structures }}$ $=\frac{5}{4}=1.25$ Three unit negative charge is being shared by four $\mathrm{O}$ atoms. Formal charge $=-3 / 4$

Hence, the correct answer is option: 'C'.