Question

Consider the structure of HNO$_3$:
Select the correct option having formal charge of I, II, III and IV respectively.

• A. -1, 1, +1, 0
• B. 0, 0, +1, -1
• C. -1, 0, 0, +1
• D. +1, -1, 0, 0

Hint:

When calculating formal charge, ensure to account for the number of valence electrons, non-bonding electrons, and bonding electrons for each atom.

Answer 1

The Correct Option is C

Step 1: Understanding the structure of HNO$_3$.
In HNO$_3$, the nitrogen atom (N) is connected to three oxygens (O), one of which is attached to a hydrogen atom (H), and the others are double-bonded. The structure shows formal charges on the oxygen atoms.

Step 2: Calculating the formal charges.
To calculate the formal charge:
\text{Formal charge} = \text{Valence electrons} - \text{Non-bonding electrons} - \frac{\text{Bonding electrons}}{2}
For I (H):
Formal charge = 1 - 0 - 0 = -1
For II (N):
Formal charge = 5 - 0 - 4 = 0
For III (O, double bonded to N):
Formal charge = 6 - 4 - 4/2 = 0
For IV (O, single bonded to N):
Formal charge = 6 - 4 - 2/2 = +1

Step 3: Conclusion.
The formal charges for I, II, III, and IV are -1, 0, 0, and +1, respectively. Hence, the correct answer is (3).