citric-acid-hoc-cooh-ch2cooh-2-is-a-weak-triprotic-acid-write-equations-that-sho

Question

Citric acid (HOC(CO₂H)(CH₂CO₂H)₂) is a weak triprotic acid. Write balanced dissociation equations and corresponding equilibrium expressions for each dissociation step.

Accepted Answer

First Dissociation
HOC(COOH)(CH₂COOH)₂(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HOC(COO)(CH₂COOH)₂⁻(aq)
K_a1 = [H₃O⁺][HOC(COO)(CH₂COOH)₂⁻]/[HOC(COOH)(CH₂COOH)₂]
Second dissociation
HOC(COO)(CH₂COOH)₂⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq)
K_a2 = [H₃O⁺][HOC(COO)(CH₂COO)(CH₂COOH)²⁻]/[HOC(COO)(CH₂COOH)₂⁻]
Third dissociation
[HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)₂]³⁻(aq)
K_a3 = [H₃O⁺][HOC(COO)(CH₂COO)₂]³⁻]/[HOC(COO)(CH₂COO)(CH₂COOH)²⁻]

Answer

First Dissociation
HOC(COOH)(CH₂COOH)₂(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HOC(COO)(CH₂COOH)₂²⁻(aq)
K_a1 = [H₃O⁺][HOC(COO)(CH₂COOH)₂²⁻]/[HOC(COOH)(CH₂COOH)₂]
Second dissociation
HOC(COO)(CH₂COOH)₂⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq)
K_a2 = [H₃O⁺][HOC(COO)(CH₂COO)(CH₂COOH)²⁻]/[HOC(COO)(CH₂COOH)₂⁻]
Third dissociation
[HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)₂]³⁻(aq)
K_a3 = [H₃O⁺][HOC(COO)(CH₂COO)₂]³⁻]/[HOC(COO)(CH₂COO)(CH₂COOH)²⁻]

Answer

First Dissociation
HOC(COOH)(CH₂COOH)₂(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HOC(COO)(CH₂COOH)₂⁻(aq)
K_a1 = [H₃O⁺][HOC(COO)(CH₂COOH)₂⁻]/[HOC(COOH)(CH₂COOH)₂]
Second dissociation
HOC(COO)(CH₂COOH)₂⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq)
K_a2 = [H₃O⁺][HOC(COO)(CH₂COOH)₂⁻]/[HOC(COO)(CH₂COO)(CH₂COOH)²⁻]
Third dissociation
[HOC(COO)(CH₂COO)(CH₂COOH)]₂⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)₂]³⁻(aq)
K_a3 = [H₃O⁺][HOC(COO)(CH₂COO)₂]³⁻]/[HOC(COO)(CH₂COO)(CH₂COOH)²⁻]

Answer

First Dissociation
HOC(COOH)(CH₂COOH)₂(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HOC(COO)(CH₂COOH)₂⁻(aq)
K_a1 = [H₃O⁺][HOC(COO)(CH₂COOH)₂⁻]/[HOC(COOH)(CH₂COOH)₂]
Second dissociation
HOC(COO)(CH₂COOH)₂⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq)
K_a2 = [H₃O⁺][HOC(COO)(CH₂COO)(CH₂COOH)²⁻]/[HOC(COO)(CH₂COOH)₂⁻]
Third dissociation
[HOC(COO)(CH₂COO)(CH₂COOH)]²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + [HOC(COO)(CH₂COO)₂]³⁻(aq)
K_a3 = [H₃O⁺][HOC(COO)(CH₂COO)(CH₂COOH)²⁻]/[HOC(COO)(CH₂COO)₂]³⁻]

Citric acid (HOC(CO2H)(CH2CO2H)2) is a weak triprotic acid. Write balanced dissociation equations and corresponding equilibrium expressions for each dissociation step.

Citric acid (HOC(CO₂H)(CH₂CO₂H)₂) is a weak triprotic acid. Write balanced dissociation equations and corresponding equilibrium expressions for each dissociation step.