What is the name of the compound whose formula is #H_2SO_4#?

2 Answers
May 15, 2016

Here's my thought process:

  • It has hydrogen ions in the front and an anion in the back #-># it's an acid.
  • Oxygen and sulfur are both more electronegative than hydrogen, so whether hydrogen is bonded to sulfur or oxygen, its common oxidation state is likely #+1#.
  • Since these hydrogen ions have a #+1# oxidation state, #"SO"_4# has a #2-# charge to balance out the charges.
  • #"SO"_4^(2-)# has the anion prefix "sulf".
  • Since the anion has oxygens, and is a polyatomic ion, it ends in either "-ate" or "-ite". Also, that implies the name does not start with "hydro".
  • #"SO"_3^(2-)# exists, and is called sulfite. "-ate" polyatomic ions usually have more oxygens than "-ite" polyatomic ions. Thus, #"SO"_4^(2-)# is called sulfate.
  • Recall that "sulfate" #harr# "sulfuric" + acid.

Thus, the name is sulfuric acid.

Common mistakes are:

  • sulfurous acid (#"H"_2"SO"_3#)
  • hydrosulfuric acid (#"H"_2"S"#)
  • sulfic acid (nonexistent)
  • dihydrogen sulfate (it's OK, but not what is expected on a test and you may lose a few points).
May 15, 2016

Hydrogen + Sulfate ion = Sulfuric Acid.
This is one of the most common laboratory acid.