Let us first write down the balanced chemical equation:
2HCl + Ba(OH)2 --> BaCl2 + 2H2O
From this balanced equation we see that for every mole of Ba(OH)2 we need 2 moles of HCl - twice the amount of Ba(OH)2. So, from the given Ba(OH)2 concentration and given Ba(OH)2 ...
This solution explains in 217 words how to find the volume required in a reaction, using balanced chemical equations and volume formulas.