A 25.0 mL sample of 0.200 M HCO₂H(aq)is titrated with 0.100 M KOH(aq).What is the pH at the equivalence point? (K_a of HCO₂H = 1.8 $\times$ 10^-4) A) 5.71 B) 7.00 C) 8.28 D) 8.52 E) 10.26

Question

Quizplus · Accepted Answer

At the equivalence point, the formic acid (HCO2H) is completely converted to its conjugate base (HCO2^-). The pH is determined by the hydrolysis of the conjugate base. Using the formula pH = 7 + 0.5(pKa + log Cb), where Cb is the concentration of the conjugate base, the pH is approximately 8.28.

A 250 ML Sample of 0 ×\times× 10-4) A) 5

A 250 ML Sample of 0 $\times$ 10^-4)
A) 5