The pH of 1 Molar acetic acid is 2.4. By adding sodium acetate, NaCH3COO to the acetic acid a buffer solution is formed. Which statement best describes what occurs in the buffer solution?

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Correct Answer: D. Addition of the sodium acetate adds acetate ions to the solution and the acetic acid equilibrium reacts by reversing to consume some of the introduced acetate ions, thus the pH of the solution will approach 7.
According to Le Chatelier’s principle: “Any change that affects the position of an equilibrium will cause that equilibrium to shift, if possible, in such a way as to partially oppose the effect of that change.”
CH3COOH(aq) + H2O(l) <=> CH3COO–(aq) + H3O+(aq)
The addition of the sodium acetate adds acetate ions to the solution increasing the concentration of acetate ions. Thus the acetic acid equilibrium reacts by reversing to consume some of the introduced acetate ions, in doing so hydronium ions are also consumed and thus the solution becomes less acidic and pH of the solution will approach neutral, 7.
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