Question

If the value of ionisation
constant of acetic acid is equal
to the ammonium
hydroxide,then the pH of
ammonium acetate will be *​

Answer 1

Explanation:

Ammonium acetate is a salt of weak acid, acetic acid and weak base, ammonium hydroxide.

When weak acid and base is given in a mixture, the pH of ammonium acetate is calculated as:

pH=7+

2

1

(pk

a

−pk

b

)

⟹pH=7+

2

1

(4.76−4.75)=7.005

Hope it is Helpful

Answer 2

Given: The value of the ionisation constant of acetic acid is equal to the ammonium hydroxide.

To find: We have to find the pH of ammonium acetate.

Solution:

Acetic acid is a weak acid and ammonium hydroxide is a weak base. They form a salt ammonium acetate.

Let the ionisation constant for acetic acid is Ka and for ammonium hydroxide Kb.

The relationship between Ka and pKa or Kb and pKb is as follows-

pKa=-log(Ka) or pKb=-log(Kb)

As Ka=Kb so, pKa=pKb.

Again we know that-

pH=7+1/2(pKa-pKb)

pH=7+1/2(pKa-pKa)

pH=7+0

pH=7

The pH of the ammonium acetate is 7.