A 25.0 mL sample of 0.150 mol L^-1 butanoic acid is titrated with a 0.150 mol L^-1 NaOH solution. What is the pH before any base is added? Butanoic acid is monoprotic. The K_a of butanoic acid is 1.5 × 10^-5. A)2.83 B)1.5 × 10^-3 C)4.82 D)4.00 E)1.0 × 10⁴

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Quizplus · Accepted Answer

The pH before any base is added can be calculated using the formula for the pH of a weak acid: pH = -log(√(Ka × [HA])). Substituting the given values: pH = -log(√(1.5 × 10^-5 × 0.150)) = 2.83.

A 250 ML Sample of 0