H3SbO4 is the chemical formula of antimonic (or stibic) acid.
The name for H3SbO4 is antimony(III) hydrogensulfate.
H3AsO4 is stronger than H3SbO4. This is because As (arsenic) is more electronegative than Sb (antimony), leading to a more acidic nature for arsenic compared to antimony.
antimony is amphoteric, so in water it will behave as an acid and a base