NEET2025ChemistryIonic EquilibriumActual
Phosphoric acid ionizes in three steps with their ionization constant values K _ a ₁ , ~K _ a ₂ and K _ a ₃ , respectively, While K is the overall ionization constant. Which of the following statements are true? A. K = K _ a ₁ + K _ a ₂ + K _ a ₃ B. H ₃ PO ₄ is a stronger acid than H ₂ PO ₄⁻ and HPO ₄²⁻ C. K_ a₁ K_ a₂ K_ a₃ D. K _ a ₁ = K _ a ₃ + K _ a ₂ 2 Choose the correct answer from the options given below:
Options
- AA and B only
- BA and C only
- CB , C and D only
- DA, B and C only
Correct answer
D. A, B and C only
Step-by-step solution
For polybasic acid, order of ionization constant is Ka ₁ Ka ₂ Ka ₃ because as negative charge increases, tendency to loose H ⁺ ions decreases. Overall K = Ka ₁ Ka ₂ Ka ₃ Taking log on both sides K = Ka ₁+ Ka ₂+ Ka ₃