WAEC Chemistry 2013 Paper

Concept:Ammonium chloride is an ionic compound made of a polyatomic cation and a simple anion.Explanation:In the ammonium ion, $\mathrm{NH}_4^+$, nitrogen forms three normal covalent bonds with three hydrogen atoms.The fourth $\mathrm{N}-\mathrm{H}$ bond is formed when nitrogen donates its lone pair to a hydrogen ion, $\mathrm{H}^+$.This bond is called a dative covalent or coordinate bond.Thus, all the bonds within $\mathrm{NH}_4^+$ are covalent, including one dative bond.The ammonium ion, $\mathrm{NH}_4^+$, and the chloride ion, $\mathrm{Cl}^-$, are held together by an ionic bond.Therefore, crystalline ammonium chloride contains ionic, covalent, and dative bonds.Answer:C. ionic, covalent and dative