Question

uppose you perform a titration of an unknown weak acid solution. You start with 4.00 mL of the weak acid and find that it takes 12.8 mL of 0.0500 M NaOH to reach the equivalence point. What is the concentration of the unknown weak acid solution?

Answer 1

Step-by-step explanation:

It is known that at the equivalence point,

Equivalent of acid = equivalent of base ......... (A)

and, Equivalent =
`\text{Molarity} * n_(f) * V`

Therefore, equivalent of acid is calculated as follows.

Equivalent of acid =
`M * 1 * 4` .......... (1)

Equivalent of base =
`0.05 * 1 * 12.8` ............ (2)

Hence, using equation (A) we will calculate the concentration as follows.

`M * 4 = 0.05 * 12.8`

M = 0.16 M

Thus, we can conclude that concentration of the unknown weak acid solution 0.16 M.