Question

The next 11 questions are related to the titration of 40.00 mL of a 0.0900 M acetic acid solution with 0.0700 M KOH. Assume that the temperature is 25 oC. What is the initial pH of the analyte solution?

Answer 1

2.9 is the initial pH of the analyte solution.

Step-by-step explanation:

The dissociation constant of acetic acid as per theoretical value =
`K_a`

`K_a=10^(-4.756)=1.8* 10^(-5)`

The initial concentration of acetic acid = c = 0.0900 M

`HAc\rightleftharpoons Ac^-+H^+`

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

`K_a=([Ac^-][H^+])/([HAc])`

`1.8* 10^(-5)=(x* x)/((c-x))`

`1.8* 10^(-5)=(x* x)/((0.0900-x))`

Solving for x:

x = 0.001264 M

`[H^+]=0.001264 M`

The pH of the solution :

`pH=-\log[0.001264]=2.898\approx 2.9`

2.9 is the initial pH of the analyte solution.