Question

n unknown weak acid, HA, it titrated with 0.6 M NaOH. The pH at the halfway point of this titration was found to be 4.215. If the initial pH of the weak acid solution (before titration) has a pH of 2.148, what was the concentration of the weak acid solution

Answer 1

Answer:

The concentration of the weak acid was the antilog of the initial pH =  7.112 × $10^{-3}$ M

Explanation:

We are given the initial pH of the weak acid HA to be = 2.148.

Since pH = - log [HA]

⇒ [HA] = $10^{-pH} = 10^{-2.148}$

[HA] = 7.112 × $10^{-3}$ M ≡ 0.0007112 M