What is the correct name for the ionic compound with the formula CaSO_4?

• A. Calcium sulfide
• B. Calcium sulfur oxide
• C. Calcium sulfite
• D. Calcium sulfate

Answer: (D)

Verified step by step guidance

1. Identify the cation and anion in the compound CaSO_4. The cation is Ca^{2+} (calcium ion) and the anion is SO_4^{2-} (sulfate ion).
2. Recall the common polyatomic ions and their charges. SO_4^{2-} is the sulfate ion, while SO_3^{2-} is the sulfite ion.
3. Since the formula contains SO_4^{2-}, the correct name for the anion part is 'sulfate'.
4. Combine the name of the cation (calcium) with the name of the anion (sulfate) to form the compound name: 'calcium sulfate'.
5. Verify that the charges balance to form a neutral compound: Ca^{2+} and SO_4^{2-} combine in a 1:1 ratio, confirming the formula CaSO_4 corresponds to calcium sulfate.