Which of the following statements correctly describes the Lewis dot structure of the hydronium ion (H3O+)?

• A. Oxygen is bonded to two hydrogen atoms and has two lone pairs; the positive charge is due to the gain of one proton.
• B. Oxygen is bonded to four hydrogen atoms and has no lone pairs; the positive charge is due to the loss of one electron.
• C. Oxygen is bonded to three hydrogen atoms and has two lone pairs; the positive charge is due to the loss of one proton.
• D. Oxygen is bonded to three hydrogen atoms and has one lone pair; the positive charge is due to the loss of one electron.

Answer: (D)

Verified step by step guidance

1. Recall that the hydronium ion (H3O+) is formed when a water molecule (H2O) gains a proton (H+). This means the oxygen atom in H3O+ is bonded to three hydrogen atoms.
2. Determine the number of lone pairs on the oxygen atom. In water (H2O), oxygen has two lone pairs. When it forms H3O+, one of the lone pairs is used to bond with the additional hydrogen, leaving oxygen with one lone pair in H3O+.
3. Understand the source of the positive charge. The positive charge on H3O+ arises because the oxygen atom has accepted a proton (H+), which is a hydrogen nucleus without an electron, effectively resulting in a loss of one electron relative to the neutral water molecule.
4. Summarize the Lewis structure: oxygen bonded to three hydrogens, one lone pair on oxygen, and an overall +1 charge due to the gain of a proton (loss of one electron).
5. Compare the given statements with these conclusions to identify the correct description of the hydronium ion's Lewis structure.