If a buffer solution is 0.270 M in a weak acid ( 𝐾a=5.4×10−5) and 0.500 M in its conjugate base, what is the pH?

Answer 1

Henderson Hasselbalch equation:

pH = pKa + log [conj.base]/[acid]

pKa = -log Ka = 4.27

pH = 4.27 + log (0.500/0.270) = 4.27 + 0.27

pH = 4.54