SUMMARY
The end point pH when 50 mL of 0.2 mol/L HCl reacts with 50 mL of 0.2 mol/L NH3 is determined by the formation of NH4Cl in solution. At the equivalence point, the solution contains NH4+ ions, which are responsible for the pH change. Given that NH3 has a Kb of 1.8x10^-5, the resulting pH can be calculated using the hydrolysis of NH4+, leading to a pH of approximately 5.1.
PREREQUISITES
- Understanding of acid-base reactions and neutralization.
- Knowledge of the dissociation constants (Kb and Ka) for weak bases and acids.
- Familiarity with the concept of equivalence points in titrations.
- Basic skills in performing pH calculations using equilibrium expressions.
NEXT STEPS
- Study the hydrolysis of ammonium ions (NH4+) in aqueous solution.
- Learn how to calculate pH at the equivalence point in acid-base titrations.
- Explore the relationship between Kb and Ka for weak acids and bases.
- Investigate the concept of buffer solutions and their pH stability.
USEFUL FOR
Chemistry students, educators, and anyone involved in acid-base chemistry or titration experiments.