Chemistry · Ionization of water, pH scale, common ion effect, hydrolysis of salts and pH of their solutions, the solubility of sparingly soluble salts, solubility products and buffer solutions

for acetic acid in water is at The of a mixture of 25 of acetic acid and of 0.1N

\( K_{a} \) for acetic acid in water is \( 1.7 \times \) \( 10^{-5} \) at \( 25^{\circ} \mathrm{C} . \) The \( \mathrm{pH} \) of a mixture of 25 \( \mathrm{ml} \) of \( 0.02 \mathrm{N} \) acetic acid and \( 2.5 \mathrm{ml} \) of 0.1N NaOH (neglecting volume change) will be \( (\log 1.7=0.23) \)

  • A. 2.
  • B. 4.8
  • C. 7 .5 \)
  • D. 1.0.

Step-by-step solution

Moles of CH3COOH = 0.025 L × 0.02 M = 0.0005 mol; moles of NaOH = 0.0025 L × 0.1 M = 0.00025 mol. Reaction consumes equal moles, leaving 0.00025 mol each of CH3COOH and CH3COO⁻. Henderson-Hasselbalch: pH = pKa + log([salt]/[acid]) = -log(1.7×10⁻⁵) + log(1) = 4.77 ≈ 4.8.
Practise more in this unitView MCQsSign up for full question bank