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

May 15, 2016

Here's my thought process:

• It has hydrogen ions in the front and an anion in the back $\to$ 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, ${\text{SO}}_{4}$ has a $2 -$ charge to balance out the charges.
• ${\text{SO}}_{4}^{2 -}$ 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".
• ${\text{SO}}_{3}^{2 -}$ exists, and is called sulfite. "-ate" polyatomic ions usually have more oxygens than "-ite" polyatomic ions. Thus, ${\text{SO}}_{4}^{2 -}$ is called sulfate.
• Recall that "sulfate" $\leftrightarrow$ "sulfuric" + acid.

Thus, the name is sulfuric acid.

Common mistakes are:

• sulfurous acid (${\text{H"_2"SO}}_{3}$)
• hydrosulfuric acid ($\text{H"_2"S}$)
• 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.