Which of the following is the correct chemical formula for ammonium sulfite?

• A. (NH_4)_2SO_4
• B. NH_4SO_3
• C. NH_4_2SO_3
• D. (NH_4)_2SO_3

Answer: (D)

Verified step by step guidance

1. Identify the ions involved: ammonium is the polyatomic ion NH_4^+ and sulfite is the polyatomic ion SO_3^{2-}.
2. Determine the charges on each ion: ammonium (NH_4^+) has a charge of +1, and sulfite (SO_3^{2-}) has a charge of -2.
3. Balance the total positive and negative charges to form a neutral compound. Since sulfite has a charge of -2, you need two ammonium ions (each +1) to balance it.
4. Write the formula by placing the ammonium ion in parentheses with a subscript 2 to indicate two ammonium ions, followed by the sulfite ion: (NH_4)_2SO_3.
5. Verify that the formula is electrically neutral by confirming that the total positive charge (+2 from two NH_4^+) balances the total negative charge (-2 from SO_3^{2-}).