Question

Marshall's acid is

Answer 1

Marshall's Acid

1. Marshall Acid is ${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_8$ known as peroxydisulfuric acid.
2. It is also known as oxoacid of Sulfur. Oxoacids mean the compound has at least one doubly bonded oxygen atom and one singly bonded hydroxyl group. The structure is given below-

3. This compound contains one peroxy linkage, two doubly bonded oxygen atoms with sulfur and one hydroxyl group.

Therefore, Marshall's acid is peroxodisulfuric acid (${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_8$).