of acetic acid is mixed with of sodium acetate solution. Assuming for acetic acid, find the exact pH — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

Milliequivalents (or millimoles, since n-factor=1 for both) of acid = $50 \times 2 = 100 \text{ mmol}$. Millimoles of salt = $10 \times 1 = 10 \text{ mmol}$. Using the Henderson equation: $pH = pK_a + \log\frac{[Salt]}{[Acid]} = 5 + \log\left(\frac{10/V}{100/V}\right) = 5 + \log(0.1) = 5 - 1 = 4$.