Question

A 0.498 M aqueous solution of C₅H₅N has a pH of 9.44. Calculate the pH of a buffer solution that is 0.498 M in C₅H₅N and 0.160 M in C₅H₅NH+

Answer 1

To calculate the pH of a buffer solution, you need to consider the concentration of both the weak acid and its conjugate base. In this case, the buffer solution is 0.498 M in C₅H₅N and 0.160 M in C₅H₅NH+. First, find the pKa of C₅H₅N using the formula: pKa = pH + log([C₅H₅NH+]/[C₅H₅N]). Then, use the Henderson-Hasselbalch equation to calculate the pH of the buffer solution: pH = pKa + log([C₅H₅NH+]/[C₅H₅N]).

Step-by-step explanation:

To calculate the pH of a buffer solution, you need to consider the concentration of both the weak acid and its conjugate base. In this case, the buffer solution is 0.498 M in C₅H₅N and 0.160 M in C₅H₅NH+. First, find the pKa of C₅H₅N using the formula:

pKa = pH + log([C₅H₅NH+]/[C₅H₅N])

Then, use the Henderson-Hasselbalch equation to calculate the pH of the buffer solution:

pH = pKa + log([C₅H₅NH+]/[C₅H₅N])