Final answer:
To determine the molarity of the HCl solution, calculate the moles of aniline and use stoichiometry to find the moles of HCl. At the equivalence point, aniline is fully consumed, leaving only hydroxide ion. Calculate the concentration of hydroxide ion using the molarity and volume of HCl at the equivalence point, and use the pOH equation and Kw to find the pH.
Step-by-step explanation:
In this titration, aniline (a weak base) is being titrated with hydrochloric acid (a strong acid). At the equivalence point, the moles of aniline will react completely with the moles of hydrochloric acid. Therefore, we can calculate the moles of aniline using the given mass and molar mass, and then use stoichiometry to calculate the moles of hydrochloric acid required. Based on this, we can determine the molarity of the HCl solution.
To find the pH at the equivalence point, we can consider the reaction between aniline and water:
C6H5NH3+ + H2O ⇌ C6H5NH2 + H3O+
Since aniline is a weak base, it will partially react with water to form anilinium ion (C6H5NH3+) and hydroxide ion (OH-). At the equivalence point, aniline is completely consumed and we only have the hydroxide ion remaining. The concentration of hydroxide ion can be calculated using the molarity of the HCl solution and the volume at the equivalence point. Then, we can use the pOH equation and Kw to find the pH at the equivalence point.