When NH_4NO_3 is dissolved in water, which ions are formed?

• A. NH_3 and NO_2^-
• B. NH_4^+ and NO_3^-
• C. NH_3 and NO_3^-
• D. NH_4^+ and NO_2^-

Answer: (B)

Verified step by step guidance

1. Identify the compound given: ammonium nitrate, which has the chemical formula \(\mathrm{NH_4NO_3}\).
2. Recall that ammonium nitrate is an ionic compound composed of the ammonium ion and the nitrate ion.
3. Write the dissociation equation for ammonium nitrate in water: \(\mathrm{NH_4NO_3 (s) \rightarrow NH_4^+ (aq) + NO_3^- (aq)}\).
4. Recognize that \(\mathrm{NH_4^+}\) is the ammonium ion, a positively charged polyatomic ion, and \(\mathrm{NO_3^-}\) is the nitrate ion, a negatively charged polyatomic ion.
5. Conclude that when \(\mathrm{NH_4NO_3}\) dissolves in water, it forms \(\mathrm{NH_4^+}\) and \(\mathrm{NO_3^-}\) ions, not \(\mathrm{NH_3}\) or \(\mathrm{NO_2^-}\).