Answer:
Ka = 1.5 -10^-5
Explanation:
Step 1: Data given
Molarity of the solution = 0.25 M
pH = 2.71
Step 2 The equation
C3H7COOH + NaOH ⇆ C3H7COONa + H2O
Step 3: Calculate pKa
pH = (pKa-log[acid])/2
2pH = pKa -log[acid]
pKa = 2pH +log[acid]
⇒with pH = 2.71
⇒with log[acid] = -0.60
pKa=2*2.71 -0.60
pKa = 5.42 - 0.60
pKa = 4.82
Step 4: Calculate Ka
pKa = -log(Ka)
Ka = 10^-4.82
Ka = 1.5 -10^-5
