Question 1
Multiple choiceMedium1 markFour oxygen-containing species are compared: OH, OH⁻, H₂O and H₃O⁺. Which analysis correctly identifies a radical and predicts its reactivity from its electron arrangement?
Show answer and explanation
Answer: C. Neutral OH has 6 + 1 = 7 valence electrons. Its Lewis representation has one unpaired electron, so it is a radical and is expected to be highly reactive.
A: omits the extra electron from the negative charge; OH⁻ has 8 valence electrons, all paired. B: counts H₂O correctly but mistakes paired lone-pair electrons for an unpaired electron. D: fails to subtract one electron for the positive charge; H₃O⁺ has 8 valence electrons, all paired.
Remember: add an electron for a negative charge and subtract one for a positive charge.