Final answer:
The pH of the ammonia buffer solution with 0.18 M NH4+ and 0.13 M NH3 and a pKa of 9.24 is calculated using the Henderson-Hasselbalch equation and is approximately 9.10.
Step-by-step explanation:
The question asks about the pH of an ammonia buffer solution containing 0.18 M NH4+ and 0.13 M NH3, with the pKa of ammonium being 9.24. To calculate the pH of a buffer solution, we use the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])
Where [A-] is the concentration of the base form (in this case NH3) and [HA] is the concentration of the acid form (in this case NH4+). Plugging in the given values:
pH = 9.24 + log(0.13/0.18)
Calculating the log part gives us:
pH = 9.24 + log(0.7222)
pH = 9.24 - 0.1411
pH = 9.0989
Thus, the pH of the buffer is approximately 9.10.