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

The concentration of the weak acid was the antilog of the initial pH = 7.112 ×
`10^(-3)` M

Step-by-step 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