A 25.0 mL sample of 0.150 mol L^-1 formic acid is titrated with a 0.150 mol L^-1 NaOH solution.What is the pH at the equivalence point? The $K _ { a }$ of formic acid is 1.8 × 10^-4. A)11.38 B)10.26 C)5.69 D)8.31 E)7.00

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Quizplus · Accepted Answer

At the equivalence point, formic acid is converted to its conjugate base, formate ion. The pH is determined by the hydrolysis of the formate ion, which is a weak base. The pH is calculated using the formula pH = 7 + 0.5(pKa + log C), where C is the concentration of the conjugate base. This results in a pH of approximately 8.31.

A 250 ML Sample of 0 KaK _ { a }Ka​

A 250 ML Sample of 0 $K _ { a }$