<p>25 mL of a solution of barium hydroxide on titration with 0.1 M solution of HCI gave a titre value of 35 mL. The molarity of Ba<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mfenced><mrow><mi>O</mi><mi>H</mi></mrow></mfenced><mn>2</mn></msub></math>&nbsp;is:</p>