The image displays four chemical structures:
Structure 1:
This is a general formula for a polysulfuric acid or peroxodisulfuric acid derivative. The structure is HO-S(=O)2-Sx-S(=O)2-OH, where 'Sx' indicates a chain of sulfur atoms. If x=1, it would be disulfuric acid. If Sx is an oxygen atom, it represents a peroxosulfuric acid derivative.
Structure 2:
This structure represents peroxodisulfuric acid (also known as persulfuric acid). Its formula is HO-S(=O)2-O-O-S(=O)2-OH.
Structure 3:
This structure represents disulfuric acid (also known as pyrosulfuric acid or oleum). Its formula is HO-S(=O)2-O-S(=O)2-OH.
Structure 4:
This structure represents sulfuric acid. Its formula is HO-S(=O)2-OH.
Summary:
The structures shown are: a general polysulfuric/peroxodisulfuric acid derivative, peroxodisulfuric acid, disulfuric acid, and sulfuric acid.