Final answer:
The incorrect name/formula pair from the given list is D. sodium sulfate / Na₂SO₃, as the correct formula for sodium sulfate is Na₂SO₄, not Na₂SO₃, which is sodium sulfite.
Step-by-step explanation:
To identify the name/formula pair that is not correctly matched from the given list of ionic compounds, let's review each option:
- A. sodium sulfide / Na₂S: This is correct. Sodium (Na) has a +1 charge, and sulfide (S) has a -2 charge. Two sodium ions are needed to balance one sulfide ion, resulting in Na₂S.
- B. ammonium nitrate / NH₄NO₃: This is correct. Ammonium (NH₄⁺) has a +1 charge, and nitrate (NO₃⁻) also has a -1 charge. One of each balances to form NH₄NO₃.
- C. zinc hydroxide / Zn(OH)₂: This is correct. Zinc (Zn) typically has a +2 charge, and hydroxide (OH) has a -1 charge. Two hydroxide ions are needed to balance one zinc ion, resulting in Zn(OH)₂.
- D. sodium sulfate / Na₂SO₃: This is incorrect. Sodium has a +1 charge, but sulfate has a -2 charge, and its correct formula is Na₂SO₄. The given formula, Na₂SO₃, is actually for sodium sulfite.
- E. calcium oxide / CaO: This is correct. Calcium (Ca) has a +2 charge, and oxide (O) has a -2 charge. One of each balances to form CaO.
Therefore, the incorrect name/formula pair is D. sodium sulfate / Na₂SO₃.