MolSynapsequestion bank
MolSynapse / Question bank / Ionic Equilibrium I / Buffer solutions and Henderson equation
JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ie164

For a buffer made from 0.30 mol HA and 0.60 mol NaA in 1.0 L (, ), select the correct statements.

  1. ApH = 5.04
  2. BAdding 0.10 mol HCl gives pH = 4.74 + log(5/4) approximately 4.84
  3. CAdding 0.60 mol NaOH keeps it a buffer
  4. DAdding 0.30 mol HCl gives pH = 4.74

Answer: A, B

pH = 4.74 + log 2 = 5.04. 0.10 mol HCl: acid 0.40, salt 0.50, pH = 4.74 + log(1.25) = 4.84. 0.60 mol NaOH exceeds the acid (0.30 mol) so free excess NaOH remains: not a buffer. 0.30 mol HCl gives acid 0.60, salt 0.30, pH = 4.74 - 0.301 = 4.44, not 4.74.
Practice Ionic Equilibrium I More on Buffer solutions and Henderson equation
Previous questionNext question

More questions on Buffer solutions and Henderson equation