J.R. S. answered 10/11/18
Ph.D. University Professor with 10+ years Tutoring Experience
Sb in SbO^+ is 3+
Sb in Sb2O5 is 5+
Sb has been oxidized
Cd^2+ On left side is 2+
Cd as Cd on right side is zero
Cd^2+ has been reduced
Cd^2+ is the oxidizing agent
SbO^+ is the reducing agent