A 1.0500g sample of a solid weak organic base (it is known that the base contains one amine group and therefore reacts with one proton) is dissolved in 50.0mLs of 0.2500M standard hydrchloric acid. After the reaction, the excess acid is titrated to a phenolphthalein endpoint using 19.66mLs of standard 0.1837M sodium hydroxide.
Calculate the molar mass of the organic base. A second 0.5155g sample of the weak base is carefully neutralized with the standard acid solution. The solution pH is then found to be 2.750.
A) Calculate the dissociation constant of the organic base.
B) What would be the titration error if the addition of the hydrchloric acid has stopped at the green color of the bromothymol blue endpoint (pH = 6.90)?