Question #58145

1 Answer
Jul 10, 2015

Your molecule contains 4 pi bonds.


In order to determine how many pi bonds a molecule has, you need to examine its Lewis structure, more specifically you need to look for double or triple bonds.

Keep in mind that

  • a single bond is also a sigma bond;
  • a double bond contains one sigma and one pi bond;
  • a triple bond contains one sigma and two pi bonds;

The Lewis structure for dithionic acid, #H_2S_2O_6#, looks like this

Notice that the molecule has 4 double bonds, all of them between sulfur and oxygen atoms.

SInce each double bond contains one pi bond, the molecule will have a total of 4 pi bonds - one from each of the double bonds.

By comparison, the molecule has 9 sigma bonds - one for each double bond and one for each single bond (the single bonds that exist between the hydrogen and oxygen atoms are not shown).