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Write an equation including the pKa value that describes the reaction of acetic acid with aqueous NaOH.

User Archdoog
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Answer:

CH₃COOH + NaOH → NaCH₃COO + H₂O

CH₃COO⁻ + H₂O ⇄ CH₃COOH + OH⁻ pKa = 4.75

Step-by-step explanation:

Acetic acid and NaOH make a neutralization reaction, where a salt and water are formed.

CH₃COOH + NaOH → NaCH₃COO + H₂O

Acetic acid gives protons to medium

  • CH₃COOH → CH₃COO⁻ + H⁺

NaOH gives hydroxides to medium

  • NaOH → Na⁺ + OH⁻

When we have protons and hydroxides, we can produce water. That's why it is a neutralization reaction.

The acid is weak, so the formed CH₃COO⁻ becomes in the conjugate strong base. This anion can make hydrolysis to water.

CH₃COO⁻ + H₂O ⇄ CH₃COOH + OH⁻ pKa = 4.75

The NaOH is a strong base, so the Na⁺, as the conjugate weak acid, can't make hydrolysis.

We can't make this equilibrium.

Na⁺ + H₂O ⇄ NaOH + H⁺ IMPOSSIBLE

User Jon Shadforth
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