Question

The formal charges on the atoms marked as (1) to (4) in the Lewis representation of \( \mathrm{HNO_3} \) molecule respectively are

• A. \(+1,\,0,\,0,\,-1\)
• B. \(0,\,-1,\,0,\,+1\)
• C. \(0,\,+1,\,0,\,-1\)
• D. \(0,\,0,\,-1,\,+1\)

Hint:

Formal charges help identify the most stable Lewis structure and charge distribution in a molecule.

Answer 1

The Correct Option is A

1. Identify the atoms marked as (1), (2), (3), and (4):
   • (1) Oxygen bonded to Hydrogen.
   • (2) Oxygen bonded to Nitrogen.
   • (3) Nitrogen.
   • (4) Oxygen (double bonded to Nitrogen).
2. Recall the formula for calculating formal charge:

\(\text{Formal Charge} = (\text{Valence Electrons}) - (\text{Non-bonding Electrons}) - \frac{1}{2} (\text{Bonding Electrons})\)

1. Calculate the formal charges:
   • For Oxygen (1):
     \(6 - 4 - \frac{1}{2}(2) = +1\).
   • For Oxygen (2):
     \(6 - 4 - \frac{1}{2}(4) = 0\).
   • For Nitrogen (3):
     \(5 - 0 - \frac{1}{2}(8) = 0\).
   • For Oxygen (4):
     \(6 - 6 - \frac{1}{2}(2) = -1\).

Conclusion: The formal charges on the atoms marked as (1) to (4) in \( \mathrm{HNO_3} \) are \(+1,\,0,\,0,\,-1\). Thus, the correct answer is \(+1,\,0,\,0,\,-1\).