Which of the following is the sulfate ion?

Which of the following is the sulfate ion?

• A. Sulfite
• B. Sulfate
• C. Nitrate
• D. Phosphate

Answer: (B)

In oxyanion chemistry, the sulfate ion is the sulfur-containing ion with four oxygens and a 2− charge, formula SO4^2−. That distinguishes it from the others: sulfite has three oxygens (SO3^2−), nitrate contains nitrogen with three oxygens (NO3−), and phosphate has phosphorus with four oxygens but a different charge and central atom (PO4^3−). The name ending in -ate typically signals the higher-oxygen, higher-count form of the ion, so sulfate corresponds to the four-oxygen, -2 charged species. Therefore, the sulfate ion is the ion with four oxygens around sulfur and a 2− charge, SO4^2−.

In oxyanion chemistry, the sulfate ion is the sulfur-containing ion with four oxygens and a 2− charge, formula SO4^2−. That distinguishes it from the others: sulfite has three oxygens (SO3^2−), nitrate contains nitrogen with three oxygens (NO3−), and phosphate has phosphorus with four oxygens but a different charge and central atom (PO4^3−). The name ending in -ate typically signals the higher-oxygen, higher-count form of the ion, so sulfate corresponds to the four-oxygen, -2 charged species. Therefore, the sulfate ion is the ion with four oxygens around sulfur and a 2− charge, SO4^2−.