Calculate the ph for the following weak acid. a solution of hcooh has 0.14m hcooh at equilibrium. the ka for hcooh is 1.8×10−4. what is the ph of this solution at equilibrium? express the ph numerically.

- pH of the solution is 2.30.

Solution:-  The ionization equation for the given acid is written as:

Let's say the initial concentration of the acid is c and the change in concentration x.

Then, equilibrium concentration of acid = (c-x)

and the equilibrium concentration for each of the product would be x.

Equilibrium expression for the above equation would be:

From given info, equilibrium concentration of the acid is 0.14.

So, (c-x) = 0.14

hence,

Let's solve this for x. Multiply both sides by 0.14.

taking square root to both sides:

Now, we have got the concentration of .

= 0.00502 M

We know that,

pH = -log(0.00502)

pH = 2.30

So, the pH of HCOOH solution is 2.30.