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Conjugate Base in Solution

APCHEM-IEBUOL

Consider two 1 L solutions of a 0.10 M weak acid.

Weak acid A has a pH of 4.5, while weak acid B has a pH of 5.0.
Weak acid A has a $K_a = 1 × 10^{-5}$, and weak acid B has a $K_a = 1 × 10^{-4}$.

Which of the following is a true statement concerning the conjugate base in solution?

A

Weak acid B has a higher concentration of the conjugate base in solution.

B

Weak acid A has a higher concentration of the conjugate base in solution.

C

Weak acid B and weak acid A have the same concentration of the conjugate base in solution.

D

The dissociation in both solutions is so small that the conjugate base concentration is essentially ignored.