Determine how many moles of ba(oh) 2 are required to completely neutralize 0.452 mole of hc 2 h 3 o 2 .

if this were a straight reaction for stoichometry and assuming that the reaction went to completion then you would have the following:
Ba(OH)2 + 2HC2H3O2 --> Ba(C2H3O2)2 + H2O
according to the balanced equation, 1 mole Ba(OH)2 reacts with 2 moles of HC2H3O2, therefore if you have 0.113 moles acetic acid, one would require 1/2 the amount of Ba(OH)2. you would require 0.056 moles.