Question

Calculate the pH of 0.005 methonoic acid solution given that the degree of dissociation is 0.057​

Answer 1

pH = 2.77

Step-by-step explanation:

Data Given:

degree of dissociation Ka = 0.057

Concentration of Methanoic acid = 0.005 M

pH = ?

Solution:

First we calculate Hydrogen ion concentration

Formula will be used

[H⁺] =
`√(Ka . c)` . . . . . . (1)

where

Ka = degree of dissociation

c = concentration

Put values in formula 1

[H⁺] =
`√(0.057 * 0.005M)` . . . . . . (1)

[H⁺] = 0.0017 M

Now Calculate the pH

As we know

pH = -log [H⁺] . . . . . .(2)

Put values in equation

pH = - log [ 0.0017 M]

pH = - [-2.77]

pH = 2.77

So,

pH of methanoic acid = 2.77