Which is the most reasonable Lewis structure for hydrogen peroxide (H2O2)? A B D
The Correct Answer and Explanation is:
The correct answer is: B
Explanation:
Hydrogen peroxide (H₂O₂) consists of two hydrogen atoms and two oxygen atoms. To determine the most reasonable Lewis structure, we need to follow basic rules:
Step 1: Count total valence electrons
- Hydrogen (H): 1 electron × 2 = 2 electrons
- Oxygen (O): 6 electrons × 2 = 12 electrons
- Total = 2 + 12 = 14 valence electrons
Step 2: Structure requirements
- Hydrogen forms only 1 bond and does not carry lone pairs in stable Lewis structures.
- Oxygen typically forms 2 bonds and has 2 lone pairs.
- In H₂O₂, the two oxygen atoms are bonded to each other, and each is also bonded to a hydrogen atom.
Step 3: Evaluate each choice
- A: One oxygen has a double bond with the other oxygen. This creates one oxygen with only 6 electrons (violating the octet rule) and places a double bond between oxygens, which is not typical for hydrogen peroxide.
- B: Each hydrogen is singly bonded to an oxygen, and the two oxygens are singly bonded to each other. Each oxygen has two lone pairs and two bonds, fulfilling the octet rule. This is correct.
- C and D: Both have double bonds between the oxygen atoms, which is incorrect for H₂O₂. These structures do not reflect the known structure and properties of the molecule.
Conclusion:
Option B correctly represents the single bonds between H–O and O–O, and includes proper lone pairs and formal charges, matching both the experimental geometry and electronic configuration of H₂O₂. This makes B the most reasonable Lewis structure for hydrogen peroxide.
