Catalyzes the transfer of sulfate to position 4 of the N-acetylgalactosamine (GalNAc) residue of chondroitin. n 3'-phosphoadenylyl sulfate + chondroitin beta-D-glucuronate = n adenosine 3',5'-bisphosphate + chondroitin 4'-sulfate + n H(+) Belongs to the sulfotransferase 2 family.