Final answer:
To calculate the pH after the addition of different volumes of titrant in the titration of NH₃ with HCl, you can use the Henderson-Hasselbalch equation.
Step-by-step explanation:
In this titration, we are reacting 0.050 M NH₃ (aqueous ammonia) with 0.025 M HCl (hydrochloric acid). The reaction between NH₃ and HCl can be represented as follows:
NH₃ + HCl → NH₄Cl
Since NH₃ is a weak base and HCl is a strong acid, the reaction will go to completion and form NH₄Cl. NH₄Cl is a salt that dissociates completely in water, resulting in NH₄+ and Cl- ions. The NH₄+ ions will react with water to produce NH₄OH, which is a weak base. This weak base will undergo hydrolysis and produce OH- ions, increasing the pH of the solution.
The pH of the solution after the addition of the following volumes of titrant can be calculated using the Henderson-Hasselbalch equation:
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- For 0.00 mL: The initial solution contains only NH₃, so the pH will be determined by the dissociation of NH₃.
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- For 25.00 mL: The added HCl will react with NH₃ to form NH₄Cl. The pH will depend on the dissociation of NH₄+.
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- For 12.50 mL: The added HCl will react with NH₃ to form NH₄Cl. The pH will depend on the dissociation of NH₄+.
Using the Henderson-Hasselbalch equation, you can calculate the pH for each of the volumes of titrant added.