Final answer:
The pH of a buffer solution containing equal concentrations of H2CO3 and NaHCO3 is 6.35, calculated using the Henderson-Hasselbalch equation.
Step-by-step explanation:
A buffer solution consists of a weak acid and its conjugate base, which helps maintain a stable pH. To find the pH of this buffer solution, we need to consider the dissociation of H2CO3 (the weak acid) and the reaction of NaHCO3 (the conjugate base) in water. The pKa of H2CO3 is 6.35.
Therefore, at equilibrium, we can use the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])
Substituting the given concentrations, the pH of the buffer solution is:
pH = 6.35 + log(0.13/0.13)
= 6.35 + log(1)
= 6.35