Answer: Lone pair repulsion on oxygen atoms causes non-planar structure.
- A Lone pair repulsion on oxygen atoms causes non-planar structure
- B Both O-H bonds being chemically equivalent forces a planar geometry
- C Ordinary water adopts an identical open-book dihedral structure
- D The O-O linkage is actually a triple bond restricting rotation
Correct answer: A. Lone pair repulsion on oxygen atoms causes non-planar structure
Explanation: Each oxygen in H<sub>2</sub>O<sub>2</sub> has two lone pairs; their repulsion twists the molecule into a non-planar 'book' structure.
Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.
Concept context
The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.