Calculate the concentration (in molarity) of a Ba(OH)2 solution if 25.0 mL of the solution are needed to neutralize 20.0 mL of a 0.500 M HCl solution. The two solutions react according to the balanced equation below:
Ba(OH)2 (aq) + 2 HCl (aq) -> BaCl2 (aq) + 2 H2O (l)