Draw structures of the following: (a) H2S2O7 (b) HClO3

(a) H₂S₂O₇ (Pyrosulfuric acid)

Pyrosulfuric acid, also known as disulfuric acid, has the chemical formula H₂S₂O₇. It's formed by the reaction of sulfur trioxide (SO₃) with sulfuric acid (H₂SO₄). The structure involves two sulfur atoms each bonded to three oxygen atoms. One oxygen atom acts as a bridge linking the two sulfur atoms.

     O          O
     ||         ||
HO-S-O-S-OH
     ||         ||
     O          O

The two S atoms are sp³ hybridized, with one S-O-S bond, two S-OH bonds, and two S=O bonds. Each S atom is surrounded by four oxygen atoms in a tetrahedral geometry. The S-O-S bond is a relatively weak bond. The structure can also be represented as:

  O
  ||
HO-S-O-S-OH
  ||  
  O

(b) HClO₃ (Chloric acid)

Chloric acid, HClO₃, is a strong acid. The structure is based around a central chlorine atom. The chlorine atom is sp³ hybridized. The chlorine atom is bonded to three oxygen atoms by single bonds and one oxygen atom by a double bond. One oxygen atom is bonded to a hydrogen atom.

    O
   ||
  O-Cl-O-H
   |
    O

The Cl atom is surrounded by four electron domains (three single bonds and one double bond), with electron domain geometry tetrahedral and molecular geometry tetrahedral. The O-Cl-O bond angles are less than 109.5 degrees due to electron-electron repulsion from lone pairs of electrons on oxygen.