Question

Consider the titration of 30.0 ml of 0.050 m nh3 with 0.025 mhcl. Calculate the ph after the following volumes of titrant have been added.

Answer 1

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:

1. 
   
3. For 0.00 mL: The initial solution contains only NH₃, so the pH will be determined by the dissociation of NH₃.
4. 
   
6. For 25.00 mL: The added HCl will react with NH₃ to form NH₄Cl. The pH will depend on the dissociation of NH₄+.
7. 
   
9. 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.