Calculate the concentration of acetic acid and acetate ion in a 0.2 m acetate buffer at ph 5. the p k a of acetic acid is 4.76

[Acetic acid] = 0.07 M

[Acetate] = 0.13 M

Explanation:

pH of buffer = 5

pKa of acetic acid = 4.76

Now using Henderson-Hasselbalch equation

 ....... (1)

It is given that,

[Acetate] + [Acetic acid] = 0.2 M     ....... (2)

Now solving both the above equations

[Acetate] = 1.74[Acetic acid]

Substitute the concentration of acetate ion in equation (2)

1.74[Acetic acid] + [Acetic acid] = 0.2 M

[Acetic acid] = 0.2/2.74 = 0.07 M

[Acetate] = 0.2 - 0.07 = 0.13 M