Chemical bonds are made and broken by:
a. energy changes
c. chemical reactions
b. enzymes
d. catalysts

31.43 ml of sulfuric acid is needed to react with 23.1 g of barium peroxide.

Explanation:

For the reaction:

BaO₂(s) + H₂SO₄(aq) ⇒ BaSO₄(s) + H₂O₂(aq)

We need 1 mole of BaO₂ to react with 1 mole of H₂SO₄ and then forming 1 mole of BaSO₄ and 1 mole of H₂O₂.

We know that 4.5 M solution of H₂SO₄ means 4.5 moles of H₂SO₄ in 1000 ml of solution.

Then,

23.1 g BaO₂ × ×   ×   = 31.43 ml H₂SO₄