To a solution containing equimolar mixture of sodium acetate and aceti...
You form a buffer solution. Assuming they are both in equal molar amounts the pH will be 4.74. A little more acid pH goes down SLIGHTLY. A Little more salt (NaC2H3O2) and the pH goes up SLIGHTLY. That is the purpose of making a buffer - stable pH. Consult the Henderson/Helmholtz equation.
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To a solution containing equimolar mixture of sodium acetate and aceti...
In the given question we have sodium acetate and acetic acid
(CH3COONa + CH3COOH)
a solution of a weak acid and it's conjugate base, vice -versa, upon addition of any other kind of acid or base or salt of it's own type which would become it's conjugate base or conjugate acid respectively will never affect the pH of the actual solution.
Such solutions are called buffer solutions and they do not show change in pH upon addition of acid or base(lett it be a strong one or weak one)....
To a solution containing equimolar mixture of sodium acetate and aceti...
Explanation:
When an equimolar mixture of sodium acetate and acetic acid is prepared, it results in the formation of a buffer solution. A buffer solution is a solution that resists changes in pH when small amounts of acid or base are added to it.
Buffer Solution:
A buffer solution is composed of a weak acid and its conjugate base (or a weak base and its conjugate acid). In this case, acetic acid (CH3COOH) is a weak acid and sodium acetate (CH3COONa) is its conjugate base.
Buffer Action:
The buffer solution resists changes in pH due to the common ion effect. When a small amount of sodium acetate solution is added to the equimolar mixture, the concentration of acetate ions (CH3COO-) in the solution increases. This increase in acetate ions leads to the common ion effect, which shifts the equilibrium between acetic acid and acetate ions to the left. As a result, more acetic acid molecules dissociate to form acetate ions, consuming the added sodium acetate.
Effect on pH:
Since the equilibrium between acetic acid and acetate ions is shifted to the left, the concentration of hydronium ions (H3O+) decreases. This decrease in H3O+ ions leads to a decrease in the concentration of hydrogen ions (H+) in the solution, resulting in an increase in pH. However, the overall change in pH is minimal due to the buffer action.
Conclusion:
Therefore, when more sodium acetate solution is added to the equimolar mixture of sodium acetate and acetic acid, the pH of the mixture remains relatively unchanged. This is because the buffer solution resists changes in pH by consuming the added sodium acetate and maintaining the equilibrium between acetic acid and acetate ions.
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