<p>A solution containing&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>N</mi><msub><mi>a</mi><mn>2</mn></msub><mi>C</mi><msub><mi>O</mi><mn>3</mn></msub></math>&nbsp;and NaOH requires 300 mL of 0.1 N HCI using phenolphthalein as an indicator. Methyl orange is then added to the above titrated solution when a further 25 mL of 0.2 N HCI is required. The amount of NaOH present in solution is (NaOH = 40,&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>N</mi><msub><mi>a</mi><mn>2</mn></msub><mi>C</mi><msub><mi>O</mi><mn>3</mn></msub><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>106</mn></math>)</p>