What is the pH of an aqueous solution that contains 0.27 mol of CH3CO2H (Ka = 1.8 x 10-5) and 0.41 mol of Na+ CH3CO2- ?

Question

Answer 1

Using the Henderson Hasselbalch equation....

pH = pKa + log [salt]/[acid]

pKa = -log Ka = -log 1.8x10^-5 = 4.74

The problem does not state the volume of solution so I’m assuming it is 1 liter..

pH = 4.74 + log (0.41/0.27)

pH = 4.74 + 0.18

pH = 4.92