what is the final ph of solution by mixing 100ml of 0.05m acetate acid and 100ml of 0.1m sodium acetate ?

In the mixture, [CH₃COOH]/[CH₃COO⁻] = 0.05/0.1

CH₃COOH(aq) ⇌ CH₃COO⁻(aq) + H⁺(aq) …… Ka = 1.8 × 10⁻⁵

pH = pKa + log([CH₃COOH]/[CH₃COO⁻]) = -log(1.8 × 10⁻⁵) + log(0.05/0.1) = 4.4