MCQEasyJEE 2026Covalent Bonding & Lewis Structures

JEE Chemistry 2026 Question with Solution

The formal charges on the atoms marked as (1) to (4) in the Lewis representation of HNO3\mathrm{HNO_3} molecule respectively are

Lewis structure of nitric acid showing H–O–N=O with another O singly bonded below N; atoms marked 1 on OH oxygen, 2 on nitrogen, 3 on double-bonded oxygen, and 4 on lower singly bonded oxygen.
  • A

    (+1,0,0,1)(+1,\,0,\,0,\,-1)

  • B

    (0,1,0,+1)(0,\,-1,\,0,\,+1)

  • C

    (0,+1,0,1)(0,\,+1,\,0,\,-1)

  • D

    (0,0,1,+1)(0,\,0,\,-1,\,+1)

Answer

Correct answer:A

Step-by-step solution

Standard Method

Given: The Lewis representation of HNO3\mathrm{HNO_3} has atoms marked as (1) to (4).

Find: The formal charges on atoms (1), (2), (3) and (4).

Step 1: Recall the formula for formal charge.

Formal charge=Valence electrons(Non-bonding electrons+12Bonding electrons)\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+1.

Atom (2): Nitrogen forms four bonds and has no lone pair, giving a formal charge of 00.

Atom (3): Double-bonded oxygen has complete octet, so formal charge is 00.

Atom (4): Singly bonded oxygen with three lone pairs carries a formal charge of 1-1.

Step 3: Write the final order.

(+1,  0,  0,  1)(+1,\;0,\;0,\;-1)

Therefore, the correct option is A.

Common mistakes

  • Assigning atom (1) an oxygen formal charge of 00 is incorrect because this oxygen is bonded to both H and N in the shown structure. Count the bonding and lone-pair electrons exactly before applying the formal charge formula.

  • Treating nitrogen as negatively or positively charged by default is incorrect. Formal charge must be calculated from valence electrons, non-bonding electrons, and bonding electrons, not from intuition about electronegativity.

  • Confusing the double-bonded oxygen and the singly bonded oxygen leads to the wrong sign of charge. The singly bonded oxygen with three lone pairs carries 1-1, while the double-bonded oxygen has formal charge 00.

Practice more Covalent Bonding & Lewis Structures questions

Get unlimited AI-adaptive practice, mastery tracking, and an AI tutor that explains every step — free to start.

Related questions