---
title: "A student compares the resonance contributors of the fulminate ion, which has the connectivity \\(\\text{C}-\\text{N}-\\text{O}\\), with those of the cyanate ion, which has the connectivity \\(\\text{O}-\\text{C}-\\text{N}\\). Each ion has \\(16\\) valence electrons. Lone pairs are not shown, but every atom in each contributor has an octet.  | Ion | Resonance contributors | |—|—| | Fulminate, \\(\\text{CNO}^{-}\\) | \\(F_1:[\\text{C}\\equiv\\text{N}-\\text{O}]^{-}\\quad F_2:[\\text{C}=\\text{N}=\\text{O}]^{-}\\quad F_3:[\\text{C}-\\text{N}\\equiv\\text{O}]^{-}\\) | | Cyanate, \\(\\text{OCN}^{-}\\) | \\(Y_1:[\\text{O}-\\text{C}\\equiv\\text{N}]^{-}\\quad Y_2:[\\text{O}=\\text{C}=\\text{N}]^{-}\\quad Y_3:[\\text{O}\\equiv\\text{C}-\\text{N}]^{-}\\) |  Using formal-charge magnitude and electronegativity, which statement correctly identifies and justifies the dominant contributor to each resonance hybrid?"
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url: "https://nerd-notes.com/ubq/120037/"
date_modified: "2026-08-21T08:40:51+00:00"
---

# A student compares the resonance contributors of the fulminate ion, which has the connectivity \(\text{C}-\text{N}-\text{O}\), with those of the cyanate ion, which has the connectivity \(\text{O}-\text{C}-\text{N}\). Each ion has \(16\) valence electrons. Lone pairs are not shown, but every atom in each contributor has an octet.

| Ion | Resonance contributors |
|—|—|
| Fulminate, \(\text{CNO}^{-}\) | \(F_1:[\text{C}\equiv\text{N}-\text{O}]^{-}\quad F_2:[\text{C}=\text{N}=\text{O}]^{-}\quad F_3:[\text{C}-\text{N}\equiv\text{O}]^{-}\) |
| Cyanate, \(\text{OCN}^{-}\) | \(Y_1:[\text{O}-\text{C}\equiv\text{N}]^{-}\quad Y_2:[\text{O}=\text{C}=\text{N}]^{-}\quad Y_3:[\text{O}\equiv\text{C}-\text{N}]^{-}\) |

Using formal-charge magnitude and electronegativity, which statement correctly identifies and justifies the dominant contributor to each resonance hybrid?

A student compares the resonance contributors of the fulminate ion, which has the connectivity \(\text{C}-\text{N}-\text{O}\), with those of the cyanate ion, which has the connectivity \(\text{O}-\text{C}-\text{N}\). Each ion has \(16\) valence electrons. Lone pairs are not shown, but every atom in each contributor has an octet.

| Ion | Resonance contributors |
|---|---|
| Fulminate, \(\text{CNO}^{-}\) | \(F_1:[\text{C}\equiv\text{N}-\text{O}]^{-}\quad F_2:[\text{C}=\text{N}=\text{O}]^{-}\quad F_3:[\text{C}-\text{N}\equiv\text{O}]^{-}\) |
| Cyanate, \(\text{OCN}^{-}\) | \(Y_1:[\text{O}-\text{C}\equiv\text{N}]^{-}\quad Y_2:[\text{O}=\text{C}=\text{N}]^{-}\quad Y_3:[\text{O}\equiv\text{C}-\text{N}]^{-}\) |

Using formal-charge magnitude and electronegativity, which statement correctly identifies and justifies the dominant contributor to each resonance hybrid?

- **A.** The dominant contributors are \(F_1\) and \(Y_1\). In \(F_1\), the formal charges on \((\text{C},\text{N},\text{O})\) are \((-1,+1,-1)\), avoiding a formal charge with magnitude greater than \(1\). In \(Y_1\), the charges on \((\text{O},\text{C},\text{N})\) are \((-1,0,0)\), so the negative charge is on the most electronegative atom.
- **B.** The dominant contributors are \(F_1\) and \(Y_1\), because a contributor containing a triple bond is always more important than a contributor containing only double bonds, regardless of the formal charges.
- **C.** The dominant contributors are \(F_2\) and \(Y_1\), because the contributor with the fewest atoms carrying nonzero formal charges dominates, even if one atom has a formal charge of \(-2\).
- **D.** The dominant contributors are \(F_2\) and \(Y_2\), because a negative formal charge is more stable on the less electronegative terminal atom in each ion.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120037/*