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

Step 1: Recall the formula for formal charge.
\[ \text{Formal charge} = \text{Valence electrons} - \left(\text{Non-bonding electrons} + \frac{1}{2}\text{Bonding electrons}\right) \] Step 2: Calculate formal charge on each marked atom.
Atom (1): Oxygen bonded to hydrogen carries a formal charge of \(+1\).
Atom (2): Nitrogen forms four bonds and has no lone pair, giving a formal charge of \(0\).
Atom (3): Double-bonded oxygen has complete octet, so formal charge is \(0\).
Atom (4): Singly bonded oxygen with three lone pairs carries a formal charge of \(-1\).
Step 3: Write the final order.
\[ (+1,\;0,\;0,\;-1) \] Final Answer: \[ \boxed{+1,\,0,\,0,\,-1} \]