CHEMISTRY · Single correct · A Level · Chemistry · Bonding · Bonding
Problem
In the nitrate ion, NO₃⁻, each N–O bond length is experimentally identical. Which of the following best explains this observation?
(a) The trigonal planar geometry forces all three N–O bonds to have the same length regardless of bonding.
(b) Nitrogen expands its octet, forming three N=O double bonds simultaneously, so each bond is identical.
(c) Three equivalent resonance structures delocalize the π electrons over all N–O bonds, giving each bond the same order.
(d) The N–O bonds alternate between single and double bonds, and the measured length is simply the average of those two types of bonds.