Which of the following is the correct name for the acid with the formula H_2SO_3?

• A. Sulfic acid
• B. Hydrosulfuric acid
• C. Sulfuric acid
• D. Sulfurous acid

Answer: (D)

Verified step by step guidance

1. Identify the chemical formula given: \(\mathrm{H_2SO_3}\).
2. Recognize that this formula represents an oxyacid of sulfur, where sulfur is bonded to oxygen and hydrogen atoms.
3. Recall the naming conventions for oxyacids: acids with '-ic' suffix correspond to oxyanions ending in '-ate', and acids with '-ous' suffix correspond to oxyanions ending in '-ite'.
4. Determine the related oxyanion for \(\mathrm{H_2SO_3}\), which is \(\mathrm{SO_3^{2-}}\) (sulfite ion), indicating the acid name should end with '-ous'.
5. Conclude that the correct name for \(\mathrm{H_2SO_3}\) is 'sulfurous acid', not 'sulfuric acid' (which corresponds to \(\mathrm{H_2SO_4}\)) or the other options.