Write a balanced chemical equation for the reaction between barium peroxide and sulfuric acid.

#BaO_2 + H_2SO_4 -> BaSO_4 + H_2O_2#

Use the stoichiometry of the equation to find the number of moles of sulfuric acid reacted.

#47.5 \ g \ BaO_2xx (1 mol. BaO_2)/(169.33 \ g \ BaO_2)xx (1\ mol. H_2SO_4)/(1\ mol.\ BaO_2)#

#47.5 cancel(\ g \ BaO_2)xx (1 color(red)cancel(\ mol. BaO_2))/(169.33 cancel(\ g \ BaO_2))xx (1\ mol. H_2SO_4)/(1color(red)cancel(\ mol.\ BaO_2))#

#0.281 \ mol.\ H_2SO_4#

Now, use the molarity formula to find the volume of the sulfuric acid used.

#C_M = n/ V#

Where:

#C_M " "# is the molarity of the acid solution expressed in mol/L.

#V " "# is the volume of the acid solution expressed L.

# n" "# is the number of moles.

#V = n / C_M#

#V = ( 0.281 \ mol.)/(2.75 \ mol. L^-1)#

#V = 0.102 \ L#

#V = 102 \ mL#