Respuesta :
The law of conservation of mass states the number of atoms of each element on product side must equal the number of atoms of each element on reactant side.
Ba has 1 atom on reactant side and 1 atom on product side
O has 2 atoms on reactant side and 2 atoms on product side
H has 2 atoms on reactant side and 2 atoms on product side
[tex]SO_4[/tex] has 1 molecule on product side and 1 molecule on reactant side
Therefore the balanced equation is
[tex]BaO_2 + H_2SO_4 ==> H_2O_2 + BaSO_4[/tex]