Question

check the box before each formula that represents a ligand that is likely to form a complex with a transition metal. if there are none, please check the box below the table. ☐ $\ce{no^-_{2}}$ ☐ $\ce{kbr}$ ☐ $\ce{feo}$ ☐ $\ce{h_{2}o}$ ☐ none of the above

Explanation:

To determine ligands likely to form complexes with transition metals, we analyze each compound:

• $\ce{NO^-_{2}}$: A polyatomic ion with lone pairs, can act as a ligand (e.g., in nitrito complexes).
• $\ce{KBr}$: Ionic compound, dissociates into $\ce{K^+}$ and $\ce{Br^-}$; $\ce{Br^-}$ is a ligand, but $\ce{KBr}$ as a compound is not a ligand (it’s a salt, not a species donating to a metal center directly in this form).
• $\ce{FeO}$: Ionic solid (metal oxide), not a ligand (doesn’t donate lone pairs to a transition metal center).
• $\ce{H_{2}O}$: Neutral molecule with lone pairs on O, common ligand (e.g., aqua complexes like $\ce{[Cu(H_{2}O)_{6}]^{2+}}$).

So $\ce{NO^-_{2}}$ and $\ce{H_{2}O}$ are ligands. But since the options are checkboxes, we identify the correct ones: $\ce{NO^-_{2}}$ (has charge and lone pairs) and $\ce{H_{2}O}$ (neutral ligand with lone pairs). KBr and FeO are not ligands (KBr is a salt, FeO is a metal oxide).

Answer:

• $\boldsymbol{\ce{NO^-_{2}}}$ (check the box before $\ce{NO^-_{2}}$)
• $\boldsymbol{\ce{H_{2}O}}$ (check the box before $\ce{H_{2}O}$)